The most definately not definative PSU guide

[swiftynz]

Please note before reading:

This guide is now very old and I don't have the time to constantly update it. I suggest taking a look at the OCAU wiki (http://www.overclockers.com.au/wiki/Power_Supply_Unit) for more current information. This kind of thing is more suited to a wiki since it represents the collective knowledge of a community (this thread largely represents only one person's opinion).

***

We've had quite a lot of people asking PSU related questions lately, so here's my attempt at writing a PSU guide. Mods please sticky it if you think it's a good resource, otherwise it can fade away into the depths of the forums...

Please feel free to post suggestions, constructive criticism, corrections or any additional information I may have left out. :)

Last update: January 2006

History:
15-1-06 - General update, it was getting a bit old... Added summary section to 4th post. At least read this if you can't be bothered with the rest! Revised brand categories, seemed wrong to have Thermaltake and Seasonic in the same category...
16-6-05 - Added a link to TechReport's PSU roundup (http://techreport.com/reviews/2004q4/psus/index.x?pg=20) in the useful links section
3-6-05 - Added useful links section down the bottom.
12-4-05 - Fixed SPCR link (they updated their PSU article (http://www.silentpcreview.com/article28-page1.html) which everyone should read :p), added "PC spec guide" as a rough guide based on basic system specs, and re-arranged/tidied up the rest.
23-3-05 - Added new models, reworded a few things, added "Case brands that include good power supplies"


Choosing a PSU

A PSU (Power Supply Unit) is one of the most overlooked components of a computer system and is also one of the hardest components to select, simply because there is no common reliable standard for rating them.

Manufacturers rate their PSUs in terms of peak power, which in reality means next to nothing since often it simply isn't possible for the power supply to sustain that level of power output for more than a few seconds. In many cases it isn't possible for it to output that amount of power at all, due to limitations on how much you can put on each voltage rail simultaneously. Furthermore, this rating is easily fudged to make the PSU appear more impressive than it actually is.

Deceptive Marketing/Labelling:
PSU manufacturers use a couple of tricks to make their power supplies appear better than they are. I could plagiarise SPCR's fantastic article but I won't - so here's the link instead:
http://www.silentpcreview.com/article28-page3.html (blue box on the right: "POWER SHMOWER")

Some power supply manufacturers do actually rate their power supplies honestly (in varying degrees), hence the "wattage" ratings of PSUs are not comparable between different manufacturers. A good quality 300W psu can handle more than most 450W psus, which often makes the 300W better value for money (better quality for less, who's complaining).

So when choosing a PSU, the main objective factors you should take into consideration are:
- REAL power output
- Efficiency
- Noise (if this is important to you)
- Reliability

1. Power Output

The easiest semi-reliable way to look at the power output of a PSU is to look at the power output on each of the rails (12V, 5V and 3.3V). The 12V rail is the most important in a modern system since it powers the cpu, and thus should be given the most weighting. Older Athlon and Pentium 3 motherboards draw off the 5V rail, making that rail more important in older systems.

Many modern power supplies have dual 12V rails. This was specified by intel in the ATX2 specification, for safety reasons. Having dual 12V rails does not improve performance or stability in any way since they come from the same 12V supply. They are merely regulated so that output can not exceed 20A on any one line. All in all, dual 12V rails has only increased costs and given makers of shoddy power supplies another way to fudge their ratings. Intel has since removed dual 12V lines from the specification. See this thread (http://forums.silentpcreview.com/viewtopic.php?t=23916) at SPCR for more information on dual 12V rails.

When interpreting the specs of a PSU with dual 12V rails do not just add the two 12V rails together, since they are merely what the rails are regulated to. You need to dig deeper to find out the total 12V output power. As an example, here is the sticker for an Enermax 420W PSU:
http://swifty.orcon.net.nz/files/psu/enermax_sticker.jpg (changed to link since images are off, you'll just have to click it sorry)
You can see that this PSU has 2 12V rails, at 18A each. Added together you get 36A, yet at the end there is a "+12V total" specification of 29A (which isn't bad). Other manufacturers will show a wattage rating below the two 12V rails, eg this skyhawk psu (http://www.shg.com.tw/front/bin/ptlist.phtml?Category=62769) (this is not in any way an endorsement, in fact I would suggest avoiding this PSU like the plague). The skyhawk GM420PC has two 12V rails of 14 and 12 amps. 26amps looks fairly decent until you look at the total ouput power figure below. The GM420PC can only out put 175W at 12V. This is only 14.58 amps, which is not enough these days. And remember this is a peak figure and assumes no load on the 3.3 and 5V rails. As soon as you load up the other rails the max power availalbe at 12V drops. Other makers don't even show you the total 12V ouput at all.

For a low end system you can get away with a PSU with a 12V rail of 15A, but if you don't consider your computer to be a basic low end PC or plan to upgrade in the future, you should look for more. Most PCs should have a PSU with 20A on the 12V rail, more for high end and overclocked PCs. For an overclocked high end gaming machine, look for a PSU which exceeds 26A output at 12V. For best stability get a PSU that is as powerful as your wallet will allow.

For any new system I do not recommend using any power supply that has less than 18A on the 12V rail(s).

Overclocking increases the power drain on a PSU, but not significantly unless you raise the vcore. The best way to illustrate this is to use an example:

Using this CPU wattage calculator here (http://www.benchtest.com/calc.html) we can see that the wattage of an Athlon XP 2500+ at stock speed is 68.3 (figure from AMD). Overclocking that cpu to 2400mhz on 1.75V increase the theoretical maximum power to 100.76W. In reality however the cpu can never exceed 88% of that figure, so we take the max power consumption to be 88% of that, 88.7W in this case or 60.1W at stock.
Doing some highly complex mathematics we discover that we have increased the load on the PSU by 28.6W by overclocking the cpu alone. Translated into amps using P=VI or I=P/V, we have increased the load on the PSU by 2.4A on the 12V rail... assuming of course that your board uses the 12V rail to power the cpu.

This doesn't take in to account the inefficiency of the motherboard's VRM (voltage regulation module), or increased power draw from overclocking the FSB, ram, graphics card, or more elaborate cooling methods such as watercooling pumps. If you overclock you should not go cheap on the PSU!

2. Efficiency:

Efficiency determines how much power is wasted in the PSU. Say your PC is drawing 150W total (a very high load for normal use). A PSU with an efficiency of 70% will consume 214 watts of power (150*100/70) to supply that 150W, with the 64 watt difference dissipated as heat in the power supply. More heat means a hotter running PSU, which means more and faster fans are required to cool it (more noise), or it will suffer a shorter life span. Efficiency figures are difficult to obtain since most manufacturers don't supply them in marketing brochures, only to large OEMs.

The ATX 1.3 spec calls for at least 65% efficiency (many cheapies are below that), and a decent power supply will exceed 70%. The most efficient PSU's that I know of are the Enermax Noisetaker series, at approximately 80% as tested by silentpcreview (http://www.silentpcreview.com/article149-page1.html). These days you should look for an ATX 2.x compliant PSU since the guidelines are a little more strict.

[swiftynz]

3. Noise:

Noise is a subjective topic, and what is loud to one person is not neccessarily loud to another. When choosing a quiet PSU the most important factor is efficiency, as described above. Less heat means you can get away with changing the fans to quieter ones without causing it to burst into flames.

One thing to bear in mind is that many power supplies marketed as "silent" aren't. Quiet or "silent" psus typically use thermally controlled fans, and while they might be very quiet when you first turn them on, a less efficient PSU will heat up quickly and cause the fans speed to increase. A classic case of this is the earlier revisions of the Enermax 350W "whisper" psu. Quiet at startup, plain loud at full blast. Thermaltake are just as bad, but the worst of all is the Vantec "Stealth" PSU. Bloody loud, even at startup. Normally I wouldn't single it out, but it is marketed as a quiet PSU which is a complete fallacy.

Good quiet power supplies include Zalman models (not very high powered for the Wattage, but reliable and quiet), and the Enermax Noisetaker series. Less fans is a good thing, and some use an internal 120mm fan, another good feature in a quiet PSU. Silverstone and Seasonic also deserve mention as good quality quiet power supplies.

Completely Passive PSUs are not a good idea for most PCs. The heat from the case has to be exhausted somehow, and in ATX cases the PSU is supposed to do this job. With a passively cooled PSU you will have to extract the hot air from somewhere else, and ensure that the PSU gets enough airflow so it doesn't overheat. In other words you'd be spending money to remove one source of noise only to create another. If you do install a passive PSU in a standard layout tower case, you should consider putting a 120mm fan in the top to remove the heat.


4. Reliability:

The only real way to measure reliability is to get statistics on failure rates which is next to impossible. Browsing forums will skew results, since popular models may appear to fail more often due to a larger sample size. Buying a brand name such as Enermax, Thermaltake, Topower, Nexus, Silverstone, Seasonic or Fortron (found only in Aopen cases in NZ) will help ensure that you end up with a reliable PSU.

Another thing to bear in mind is that a psu that is pushed to its limit 24/7 will not last nearly as long as a PSU that is twiddling its thumbs. Hence buying an over powered PSU will help ensure that the PSU will run cooler and last longer. A good 350W or 400W is plenty for most.

So which one should I choose?

That depends. Some people have good experiences of particular brands and swear by them, whereas other people will warn you to stay well away.

While this article may (and should) have scared you away from cheap generic power supplies, you do not need to go nuts and get a 600W Enermax. According to Mike Chin of SPCR (read this page (http://www.silentpcreview.com/article28-page1.html)), even high end single cpu PCs can not draw much more than 300W under full load, maybe 350W for an SLI 6800 ultra rig. Most PCs draw less than 200W at full load, thus 600 watts is simply wasted capacity for most of us.

You don't have to spend more than $100 on a PSU unless you have a high end SLI PC or some other special requirement. The sweet spot appears to be $80-130.

For an idea of what to buy, read on...



PC spec guide:

Low end PC:
Sempron, AthlonXP, Celeron under 2.4ghz
MATX board
VIA/SiS/Intel Onboard video
One hard drive
One optical drive

- Could get away with almost anything, but look for a PSU that has at least an 18A 12V rail. This will give you enough capacity to add a reasonable mid-range graphics card down the track, and ensure reliability. 15 is sufficient for most low end PCs however.

Typical PC:
Single core Athlon64, Celeron, low-end P4
Low end graphics card
Two hard drives
One optical drive

- PCs in this class are fine with an 18A PSU, but ideally you want more headroom which will allow you to add a decent graphics card down the track.

Typical enthusiast PC:
Dual Core
X800, 6600, 6800 class graphics card
Two hard drives
Two optical drives

- For such a machine you should be looking for a PSU that has a pretty good 12V rail. Being enthusiasts we like to upgrade as well so some headroom is nice. An Enermax 350W will power such a machine easily, but for PCI Express motherboards you really want an ATX v2 PSU since many PCI-E graphics cards in this class are powered by the motherboard. I'd go for an Enermax 420W Noisetaker in this class. Admittedly it is bordering on overkill, but it is still priced very reasonably. As a guide for other brands, go for 24A combined on the 12V (remember don't just add the two 12V rails together - see the "power output" section above).

High End:
Dual core CPU
7800 or X1800 series graphics card
Two or more hard drives
Two optical

- At this level you really start to need a quality power supply. A 12V 26A PSU is not wasted here, and dual 12V rails are a plus to keep the graphics card isolated from the hard drives. The bare minimum to run such a system safely is probably a PSU with a 24A 12V rail, but really you need more. Those components are expensive and it is worth spending a bit more on a quality PSU. You have expensive components and it is worth spending good money on a high quality power supply to protect that investment.

Other notes:
- For 6600 SLI you should use an ATX v2 PSU that has the 24-pin motherboard connector.
- For 7800 SLI you also need an ATX v2 PSU. The 600W Enermax is overkill even in this case, but when you've got $2000 worth of graphics cards in your machine, what's another $300...
- 9700/9500 series graphics cards actually draw mainly off the 5V rail. Nvidia FX series cards draw off both the 5V and 12V rails. This should be taken into consideration if you have one of these cards, but the 5V rails on almost any decent modern PSU are usually more than adequate to handle any of these cards.
- Dual core Athlon64s use less power than single core 90nm Pentium 4's. The upcoming 60nm Pentium 4s are an improvement, but the 90nm Athlons are still more efficient, particularly at idle thanks to Cool 'n Quiet (and most cpus spend >95% of their life at idle).

[swiftynz]

Brand guide:

Everyone's experiences are different so I've tried not to be too biased and more objective while compiling the following list. Some of it I gleaned from RageX's thread here (http://forums.overclockers.co.nz/showthread.php?s=&threadid=8661&highlight=psu).

Please bear in mind that the following is a list of generalisations, and that particular models within a manufacturer's range can differ from the rest. I will also add the standard disclaimer and say that this list is only my impressions of the brands and is only to be taken as such. I will not be held responsible for any action taken as a result of reading this.

Best value:

Enermax (www.enermax.com.tw) - As much as I hate to say it, Enermax are still the best value for after-market PSUs in NZ. They are common, the returns/warranty service is excellent and I have yet to see a readily available, reasonably priced alternative. They have high specs for the ratings, particularly the all important 12V. I've always liked the brand but was sold on them when a 350W whisper I thought was faulty was tested with two 7800 GTXs in SLI running 3dmark05. They're a little pricey for some, but a worthwhile investment for anyone who wants piece of mind when building a PC.


Excellent Brands:

Antec (http://www.antec-inc.com/us/) - Historically a good solid brand, however issues have been reported recently with the Neo HE PSU - see oD1Nz's post below for details. Assuming you get a good unit, efficiency has improved markedly, and they're now in the same league as Enermax. Would be in the best value category if they were priced like enermax, but currently pricing makes them impossible to recommend for value-conscious buyers.

Acbel (http://www.acbel.com.tw/) - Specced well, reasonably priced and appear to be really good quality. They also have a good rep overseas, but could be quieter. Recommended.

Seasonic (http://www.seasonic.com) - Only sold by Advantage in Wellington as I type this. These have an excellent reputation on SPCR as being highly efficient and very quiet. If you can get one for a good price they're a very good option. Can't really put them in the best-value category when distribution is so low in this country, and warranty/returns service is a big fat "?".

Fortron (http://www.fsusa.com/) - OEM for Aopen (shipped with the cases) and Sparkle. Good choice for those on a budget since they represent good value. Models start with FSP (eg FSP-300). Good specs for the wattage rating, comparable to Enermax apart from 12V. 300W model capable of running most new systems but will lack power on the 12V rail for higher end PCs
I gather that these are included with Chenbro cases, but it may pay to check first.

Aopen (http://asia.aopen.com.tw/products/power/) - See Fortron. The model numbers are the same.

Zalman (http://www.zalmanusa.com/) - Quiet but expensive, not particularly high powered for their rating, and thus difficult to recommend. Appear to be made by Fortron.

OCZ - Excellent power supplies, but prohibitively expensive. Only recommended for ultra-high end buyers, wasted on anything mid-range.

Silverstone (http://www.silverstonetek.com) - Fairly new to this country, but they have a good rep overseas. The 650W model seems to be very good value, but the 3.3 and 5V rails are weaker than you would expect on a PSU of this rating. 400W and 460W models are underpowered compared to the closest-priced Enermax models, which keeps them out of the best-value category. Good option for those seeking a quiet PC.


Above-average brands:

Topower (http://www.topower.com/products/power.html) - Generally good PSU's, but expensive, noisy, and thus not particularly good value. OEM for Tagan, Raidmax, Powmax, and Vantec. Power supplies sold under the Topower brand appear to be better than the OEM models they supply to Raidmax and Powmax, which are pretty shoddy.

Thermaltake (www.thermaltake.com.au) - Fairly reliable but underpowered and overpriced. Misleading marketing. If you like Thermaltake's stuff then by all means go for one, but there are much better choices out there. Focus on frills and aesthetic features over actual performance. Models included with the lower-end cases are inferior to the retail models.

Superflower (http://www.super-flower.com.tw/) - Some reports of failures, but ok overall. Over-rated, don't handle big loads so well. Not quiet. (possibly OEM for Chieftec? Or uses the same OEM as Chieftec?)

Tagan (http://www.tagan.com/) - Haven't heard any anecdotal evidence here or used one myself. Not readily available. Check specifications before buying. Brand is a trademark of Topower, and one particularly model has been deemed unsafe in Finland (see this thread (http://forums.silentpcreview.com/viewtopic.php?t=16738) at SPCR - thanks oD1Nz).


Average brands:

Pro-V - I've had one of these going for 3 years without issues, so they must be fairly decent... Would not trust one to run a high powered PC. Included with Procase cases, no idea who the OEM is.

Icute - Specced OK but I wouldn't trust one in a new system. Noisy.

CWT - Unsure of these. Underpowered for the W rating.

Leadman/Powermax - These are still sold by Dick Smith and a a bit better than generic, but still inefficient.

Raidmax - Over-rated like all cheap PSUs. Not too noisy, but the quiet models are still relatively inefficient and run hot. 500W model appears to be good value at ~$60 for a 28A 12V rail, but it's only ATX1.3. Made by Topower.

JSP - All bling, no power. Stupidly over-rated, 500W model only has 18A @ 12V. :rolleyes:
Basically a generic PSU dressed up in fancy packaging. Avoid.

Skyhawk - Much the same as JSP above.


Bad Brands:

Deer - The WORST psus ever, not helped by the fact that they are cheap and so damn common. OEM for Hyena and numerous other cheapies. If you paid less than $60 for your case/psu, the chances are high that you have one of these. Appallingly high failure rate. Avoid at all costs.

Olympic - Cheaper Icute, I had one example with pathetically weak rails despite its 320W rating (12/5/3.3V read 13/5/14A :rolleyes: )

Novia - 'nuff said (http://forums.overclockers.co.nz/showthread.php?s=&threadid=4232&perpage=15&pagenumber=2)

Hairong - Anecdotal evidence here (http://forums.overclockers.co.nz/showthread.php?s=&postid=213798#post213798), could well be a Deer.

Hyena - Hyenas need no introduction, search any tech forum for Hyena and you're bound to start finding threads where the issue is a dead/dying/faulty PSU.


Case brands that include good power supplies:

Antec - Antec case, Antec power supply. Recommended, but the lower end Antec models are quite new to this country and prices are a bit steep at the moment (considering the SLK1650B, a "budget" case is US$65 in the states and NZ$200 here). If the price was $50 or more cheaper, they would be the best option hands down.

Chieftec - Stock psu is chieftec branded, could be a superflower. They're quite good power supplies, but the 420W model only has 18A on the 12V rail, which is what you'd expect in a 300-350W psu. Better than 90% of stock PSUs, roughly the equivalent of a thermaltake. I use the silver fox for many builds, simply for lack of a good cheaper option - at $160 it is too expensive for many.

Aopen - PSU is Aopen branded but they are actually made by fortron. Excellent value since at one stage the H600 series cases were only $120. But supply in NZ is non-existant.

Inwin - PSU is reportedly a sparkle, which have a very good rep. Like Aopen though, supply of these cases seems to be lacking.

Chenbro - Apparently the included power supplies are FSP (fortron), but it would pay to confirm before buying. Would be nice if we got more of the lower end no-bling models instead of the "gaming" cases.

Task - The cases are average, but the power supplies are better than most. Overall they're pretty reasonably priced too. Best budget option. edit: if you can find one... FFS.

Thermaltake - For the price you pay you could get a much nicer case without a PSU and still have enough left for an Enermax. Nothing screams kiddie gamer like a thermaltake. :D

Raidmax - Included with reservation since the included power supplies aren't exactly great, but should be sufficient to run most systems with a mid-range graphics card. Some of them are actually appalling (ie 12a 12V), would defiantely pay to check before buying.

[swiftynz]

Useful Links:

SilentPCreview PSU reviews (http://www.silentpcreview.com/section4.html) - SPCR do some of the best power supply reviews on the net and I trust their opinion implicitly.

SPCR 's "Power Supply Fundamentals & Recommendations" article (http://www.silentpcreview.com/article28-page1.html) - A must read

"Confused about dual 12V lines?" at SPCR forums (http://forums.silentpcreview.com/viewtopic.php?t=23916) - A must-read if you're evaluating any PSU that has "12V1" and "12V2" on its spec sheet.

Trustedreviews PSU test (UK) (http://www.trustedreviews.com/article.aspx?head=64&page=2279) - Good roundup of power supplies, however a lot of the models tested are not available in NZ.

Firingsquad's "Choosing the right power supply" article (http://www.firingsquad.com/guides/power_supply/) - Pretty good article, nice and easy to read and not too long. A bit dated now though.

Tech Report PSU roundup (http://techreport.com/reviews/2004q4/psus/index.x?pg=20) - Another good roundup, this link goes directly to the 12V rail AC ripple page - read this for another reason not to buy a cheap PSU. You wouldn't notice this in daily operation, but it does result in a much shorter component lifespan.


Summary of advice
Ignore total wattage ratings, except when comparing power supplies from the same manufacturer.
The old adage "you get what you pay for" has never been more true than it is in the power supply market.
Adding together the 12V rails of a multi-12v rail PSU does not give you the equivalent single 12V rail (ie a single 26A rail is far superior to two 13a 12V rails).
Efficiency is a good measure of quality. Weight is another good measure but with some "environmentally friendly" PSUs aiming for high efficiency with less metal content it doesn't always apply.
If you plan on overclocking a high-end system get the best PSU your wallet will allow.
Powering $1000 worth of components with a $50 power supply is not smart, but you could probably get away with it.
Powering $1000 worth of components with a $300 PSU is not smart either.
Trying to power $1000 worth of components with a PSU that came with a $50 case is just stupid.

:)

[Solid Snake]

My obsession with getting the biggest and most powerful system ended the day my GF4Ti4600 went from a high end price to a low end price in just a matter of weeks. Thus, all the computer parts I now buy are looked at reasonability in mind. (I no longer go out and buy the fastest most expensive Corsair ram now a days for example, but more willing to spend money on a nice big CRT/LCD or HDD since their value is much more appreciated quickly) anyways, my simple suggestion is to determine what power of PSU you actually need/want.

Needs != Wants
Incrediably, these are in fact different. Basically, those that need a top of the line PSU are those who are overclocking or those that simply draw a lot of power such as those who have a lot of IDE devices (Such as 8 HDD's). Thus, their system actually draws quite a lot of power out of the PSU to run their computer. Those that want a high end PSU are those who usually want a larger e-ego. The fact of the matter is, if you don't need the extra power a PSU can supply then why buy it?

Right now I use a 200W PSU to power a AXP 2600+, HDD, DVDRom (These three probably being the major power consumers) without any hitches what so ever. No crashes, no stalls no problems fullstop. Noise means a lot to me now a days (and it's another thing I consider when purchasing), so with a 200W PSU, producing small amounts of heat compared to a 300W or whatever , it is able to get away with using a tiny 40mm fan. Even though the 40mm fan produces very minimal amounts of CFM, it seems to be needed as some airflow is required.

In the end, if your a money/noise dependent buyer, you may want to actually rate your system and decide how much is enough for your system. That way, you might get a better deal and also a quiter PC. The trick is, is that you have to know how to calculate you think is enough for your PC, which at this point stands in theoritical/population data/experience grounds which at best can only provide a rough estimate.

[swiftynz]

Thanks for the addition Solid Snake. :)

While the 200W shuttle PSUs do run quite cool, it's not because they're less powerful, but more because they're efficient.

With the same PC and power load, a 300W PSU running at 70% efficiency will run at the same temp as a 200W psu running at 70% efficiency, but efficiency varies with load level.

At very low load the 200W would probably be more efficient but at higher loads the 300W would be more efficient, since power supplys generally are most efficient at ~60-70% of max load (obviously depending on the PSU in question). This is another reason that I recommend buying a slightly more powerful PSU than you need, so you stay reasonably close to the peak efficiency. Of course regardless of efficiency level, more load still means more heat.

You'll notice that the rails on that shuttle 200W would be better than most generic 300W psus. :)

I couldn't agree with you more about looking for reasonably priced parts. Sadly these days most of the decent graphics cards and CPU's are simply out of my price range. As a result my upgrading has slowed down considerably the last couple of years; I've had the same graphics card for nearly 2 years :eek: and the same cpu for 1 year, with absolutely nothing available that justifies the cost to upgrade.

[Forgiven]

I agree with Swifty regarding about the efficiency... The more efficient the PSU the better it is...

The highest efficiency that I have seen so far comes from Enermax Noisetaker with around 80%-82%.

[hawkz25]

Sadly these days most of the decent graphics cards and CPU's are simply out of my price range. As a result my upgrading has slowed down considerably the last couple of years; I've had the same graphics card for nearly 2 years and the same cpu for 1 year, with absolutely nothing available that justifies the cost to upgrade.

You must have been reading my mind Swifty! My geforce3 ti200 is serving me well. It's just the DX9 games e.g. Far Cry that are giving me grief now, its playable just not speedy with the eye-candy on. THe latest andgreatest VGA card are just too expensive and I can't justify $400+ for a 5900XT (or what ever $400+ buys you now) *sigh*

[osmium]

A wattage calculator or guide to power draw of components would be really handy here, I've done a google and a forum search but cant seem to find anything decent - guess I'll just have to start counting the ratings on all the components :S

[swiftynz]

Yea, to find out that information would be rather difficult for some products, as manufacturers often don't supply that information to consumers.

For any components that you do discover, post them in this thread and we can start compiling them into a cohesive list.

To start... some easy ones:

Product or component / 12V current / 5V current / 3.3V current / Total power draw
Seagate Barracuda 4 / 0.75A / 0.85A / 0A / 13.25W
Seagate Barracuda 7200.7 / 0.35A / 0.72A / 0A / 7.8W

32x CDROM (Samsung) / 1.5A / 1.0A / 0A / 23W
52X CDRW (BTC) / 1.4A / 0.8A / 0A / 20.8W

Geforce 6800 Ultra (measured, load) / 4.32A / 4.29A / 0.17A / 73.9W

Other graphics card figures can be found here (http://www.xbitlabs.com/articles/video/display/ati-vs-nv-power_10.html).

The Barracuda figures intrigue me. I wonder how seagate managed to nearly halve the power consumption of their drives...

[jpwise]

Rather an interesting site if your looking for a PSU based on specs.

http://www.newegg.com/app/manufact.asp?catalog=58&DEPA=0

gives you an option to enter various specs, and it'll spit back a list of power supplies.

Jp.

[RobbyW2]

Volcano 9 Coolmod : 12V=0.45A Total=5.4W
Those 80mm multicoloured case fans : 12V=0.15A Total=1.8W
80mm Titan Fan (DSE) : 12V=0.16A Total=1.92W
Maxtor DiamondMax Plus 9 : 5V=0.858A 12V=0.662A Total=12.23W
Pioneer DVDRW 107D : 5V=1.1A 12V=0.8A Total=15.1W

[oD1Nz]

Hate to gravedig, but I keep having to search to find this... could we please have it stickied?

[osmium]

this is great for volatge usage calculations

http://forums.overclockers.co.nz/showthread.php?s=&threadid=17415&highlight=overclockulator

[farns]

Wealth of info here (http://hardforum.com/showthread.php?t=779582)

[shaggles]

From my experience aopen isn't a bad brand either. Good reliable no frills supplies. Also on their site they list a lot of information on each supply giving their performance under a number of different loading conditions. Click the specs link on the right of the model number. Nice to see.

http://asia.aopen.com.tw/products/power/

[swiftynz]

Thanks for all the additions, I've done a minor update. Probably still needs a bit more work.

[swiftynz]

Just came in to correct a few things and it turned into a relatively major update...

(dammit that took way too long, need sleep now)

[westy159]

you were saying how low end PCs would be all right with 15A on the 12V rail yes?

When the PSU that im holding now ready to put in i believe is only 12A on the 12V rail, and this PSU is meant for a gaming PC (P4 2.66Ghz, 1GB RAM, Geforce 6800 128mb).

I just bought it and thought it would be all right as its ATX (which will fit in my case) and 400watts. But if what i think is true then this PSU is not going to be good at all.

The problem is that im not sure though. Heres what the sticker looks like (click/copy+paste the link):

http://i4.photobucket.com/albums/y137/Westy159/PSUinfo.jpg

Does that mean that the 12V rail only has 12A or am mistaken?

I need to know before wednesday really, thats when its ment to be going in the PC.

[inferno]

That image is absolutely tiny, way too small to read.

[MercuryFree]

Originally posted by westy159
you were saying how low end PCs would be all right with 15A on the 12V rail yes?

When the PSU that im holding now ready to put in i believe is only 12A on the 12V rail, and this PSU is meant for a gaming PC (P4 2.66Ghz, 1GB RAM, Geforce 6800 128mb).
That's not what I would classify as a gaming pc really....

Assuming it's a prescott core on the pentium, I highly doubt that a (assumably) Generic/cheapie power supply with only 12A on the 12V rail will be able to power it.

And yes, tiny image. I think that you've linked us to the thumbnail instead of the actual image. Silly boy :)

[westy159]

All right i couldnt get the pic to work here so i did it on another website and posted the pics on a game forum for a game that was created 8 years ago so hopefully no one will see it and delete it for it being irrelivant.

Heres the link:

http://www.gamespot.com/pc/driving/formula1/show_msgs.php?topic_id=25398383&pid=197369&msg_id=277235858

Its in link form (the top post) and in a big pic form (2nd post)
Now tell me does that thing say that theres only 12A on the 12V rail? And are there any other problems with the PSU?

BTW if i was to put the PSU in and it didnt have enough power whts thw worse that could happen? Will the PC just stop or will it ruin everything its attached to?

Please tell me if that PSU is suitable for my PC

Intel Pentium 4 @ 2.66Ghz
1GB PC2700 RAM
Geforce 6800 128mb

I know i sound desperate but thats because i am
Thank you

[Forgiven]

Originally posted by westy159
All right i couldnt get the pic to work here so i did it on another website and posted the pics on a game forum for a game that was created 8 years ago so hopefully no one will see it and delete it for it being irrelivant.

Heres the link:

http://www.gamespot.com/pc/driving/formula1/show_msgs.php?topic_id=25398383&pid=197369&msg_id=277235858

Its in link form (the top post) and in a big pic form (2nd post)
Now tell me does that thing say that theres only 12A on the 12V rail? And are there any other problems with the PSU?

BTW if i was to put the PSU in and it didnt have enough power whts thw worse that could happen? Will the PC just stop or will it ruin everything its attached to?

Please tell me if that PSU is suitable for my PC

Intel Pentium 4 @ 2.66Ghz
1GB PC2700 RAM
Geforce 6800 128mb

I know i sound desperate but thats because i am
Thank you

It is definitely 12a on the 12v rail...
Please do get another PSU...

Your system may or may not start. Probably the worse case scenario is that the PSU blow and take all your parts together with it...

[westy159]

thankyou for that as i was just about to put it in (seriously i was). Ok i'll take that back and get another. So for my PC what do i need? Wattage etc.

[Forgiven]

Originally posted by westy159
thankyou for that as i was just about to put it in (seriously i was). Ok i'll take that back and get another. So for my PC what do i need? Wattage etc.

For your system Enermax Noisetaker 420W will do...
It has plenty of amperage on the 12v rail

Check Computer Lounge out for Enermax PSU.

[swiftynz]

Finally got around to doing an update, quite a bit has changed in 6 months. Suggestions, additions or other comments appreciated. :)

[oD1Nz]

Might be worth mentioning that people still have difficulty with the Antec NeoHE (http://forums.silentpcreview.com/viewtopic.php?t=27863).

It also might be worth noting Tagan PSUs are made by the same people that that Raidmax and Powmax PSUs - ToPower. The Tagan 330W in particular has had an "unsafe" label slapped on it in Finland: http://forums.silentpcreview.com/viewtopic.php?t=16738.

[swiftynz]

Thanks for that, have revised the list a bit. I don't think trouble with one model is enough to bump Antec down a category... although given their problems with Asus and Tyan it's close. Didn't realise Tagan made such shoddy PSUs at the low end, so they've been bumped down. It's not too important since we don't actually get many of them here anyway.

If anyone has a favourable experience with a particular PSU brand, or have a brand you trust, please post. It's easy to get negative opinions but rather difficult to get positive ones.

Provide the brand, model, specifications and the main components of the system it's powering if possible. :)

[FKF]

I'm 99% sure that Chieftec and Thermaltake PSU's come out of the same factory. They are sometimes called HighPower as well.

[swiftynz]

Originally posted by FKF
I'm 99% sure that Chieftec and Thermaltake PSU's come out of the same factory. They are sometimes called HighPower as well. I know the ones you're referring to, the older ATX 1.3 420W models. Not sure if the current retail thermaltakes come from the same factory though, Thermaltake could easily use different suppliers.

[oD1Nz]

I know a lot more than what I listed come out of TopPower factories - OCZ for instance. It seems the Raidmax/cheapies have specifically requested "cheapness" from TopPower, while OCZ supposedly asked for higher quality.

The Tagan matter is curious though, given that they were supposedly (according to their website) formed because of dissatisfaction with what was currently available.

[Mantice]

I have a server a new server case. Its a cube and my current most best psu that came free in my case is a o migty oliypic "cough" I want to run another hard drive. I currently have a AMD64 - Bit 3000+ 754 512 ram and 3 hard drives allthough ones not installed yet... my current olymic psu is a 400w would upgrading to "Enermax Noisetaker PSU 420W" be enough.

The only probem is that it has to have long power cables my olymic is to short so its hanging out on the box does th Enermax have longer cables? also I think my motherboard is a 20 pin and i think thats a 24 pin PSU

Hope you guys can help me...
I dont want to have to spend over 120 bucks

[MercuryFree]

A 420W Enermax would do well, seeing as a 350W Enermax would be able to handle that with no difficulty. Also the Enermax psu's do have longer than normal cables on them, so it should be more suitable for you in that regard as well

[swiftynz]

The new Enermaxes have normal sized cables, but from memory the cables on my old Olympic were really short so they would probably be a bit longer (not much though).

420W Enermax would be more than enough power wise, but you'll have to look elsewhere for extra-long cables.

[Mantice]

Where do you think I could get Extension cables?

I hope the 24 pin will work with my 20 pin mobo

[swiftynz]

20 and 24-pin connectors are actually the same, except the 24-pin obviously has 4 extra pins. These are detachable on Enermax power supplies.

Not sure where you would get extension cables from.

[Azazel]

New and mildly interesting link, looks at 5 PSUs, including the new enermax liberty and 2 silverstones. Yes, that's right, its Tom's! (http://www.tomshardware.com/2006/02/07/5_power_supplies_get_the_full_juice_treatment/)

[Mantice]

Guess what happend to my old PSU .. .. BOOM! Smoke Powercut :( Poor Olympic... If you have one I strongly sugest that you kill it before it kills your computer (all though nothing got damaged its possable) I got my Enermax Blue PSU and it's the best thing I have bought... I started to get the shakes because I havent been on the computer for a week !!!

I could barly aford this but its so silent I cant here it !!! :)


I highly recomend this over the rest "There is no other PSU"

Well im sure there are others but I highly recomend these ones..... Cheers to the best PSU guide on the net :P

[Boyo]

I am building my first rig, but I am having trouble with chosing the correct PSU.

AMD X2 4400+
Asus A8N32-SLI Deluxe
2x eVGA 7900GT 256MB
2GB (2x 1GB) Corsair XMS 3200C2PRO
2x WD 7200.9 160GB
Lite-On DVD/CD Burner Lightscribe

Do you think the Enermax Noisetaker 600w could handle this load????

[MercuryFree]

Easily

extra letters to make up room

[swiftynz]

Yep, you're definately looking in the right class for that rig.

[IronH]

here is a link (http://www.overclockers.com.au/article.php?id=359867&P=9) to an older article that shows how much a decent PSU can improve overclocking - thought it was relevant to this thread.

I know everyone goes on about Enermax, I've had one bad experience with them, I put together a PC for my aunty a couple years ago. It had a celeron 2GHz, 256MB RAM, 20GB HDD, very low end stuff, all it had to be was reliable and silent, so I chucked in a 300W Enermax as they had a reputation for being quiet and reliable, it did run silently and was about 3x the weight as the yum cha 400W POS it replaced. 6months later it started having issues, instability, random lockups/resets etc. the reason for the problems became apparent a few days later when the PSU blew up taking out the motherboard, cpu and ram. So even with brand name PSU's dont think you are immune to such disasters.

one cheap PSU that I was pleasantly suprised with was the 450W 3R. I bought a 400W 3R for about $50 to power a sempron system, the PSU started to short out and caused instability, it was crap. So I RMA'd it. Accent sent me out a 450W version, and I couldn't believe the difference in quality between the 400W and the 450W version. the 450W version seemed like it was made by a diferent company, the build quality was much nicer and it weighed considerably more than the 400W version. it came with cable sleeving and had a nice chrome finish. the 12V rail was much higher to, 18A, still not great but better than 12A on the 400W version. but I guess it does retail at around twice the price and for that sort of money I would still go for an enermax.

[Indigo]

Is a 600w Enermax overkill for my machine?
I was told that running an SLI uses heaps of power and that this PSU would be ideal, just thought i'd check......

[zarathrustra]

For the two GTX's you've got there, its just right, nicely on the safe side. I've got the Enermax Liberty 500w, and when I can aford it, I think it'll be fine for me to run another 7900GT in SLI, but if I was going GTX SLI, I would have gone for the 600w.

BTW. very nice setup you've got their.... making me a bit jealous.

[oD1Nz]

Quick note: Looks like Mushkin are joining the PSU market (http://www.newegg.com/Product/Product.asp?Item=N82E16817812001). Once again, they are manufactured by Topower, and will likely be identical to the OCZ Modstream, Tagan and ePower that they also manufacture.

[oD1Nz]

OCZ News: the GameXStream (http://www.newegg.com/Product/Product.asp?Item=N82E16817341002) is replacing the PowerStream. Excellent news is that they appear to be rebranded Forton Epsilon (http://www.ocforums.com/showthread.php?t=454987)s. There are mixed reports surrounding noise, but it appears there was perhaps a small initial run using noisy fans; most newer reports indicate a quiet fan.

Good to see companies recognising Topower != quality.

[IronH]

here is an interesting PSU roundup by hexus (http://www.hexus.net/content/item.php?item=1359&page=19) - probably one of the best I've seen, covering over 30 PSUs. The reviewer was allowed unsupervised access to FSP's own PSU testing labs. it was interesting to see how badly Enermax PSU's performed, the two Enermax PSUs reviewed (Enermax 535W & Enermax Noisetaker 600W) both failed to supply their rated outputs for 30mins. Where as the three Thermaltake PSUs reviewed (purepower 460W, purepower 480W, & Purepower 500W) all managed to supply their rated outputs for 30mins.

Another interesting thing was the Enermax PSUs could only supply 130W on the combined power for 3.3V and 5V before turning itself off, even the 460W Thermaltake could do 230W. Also the Enermax Noisetaker 600W is rated for 34A on the 12V rail, but could only do just over 27A before turning itself off. but at least it didn't blow up like some other PSU did.

The Noisetaker 600W suffered the same problems that the previous Enermax did. Anything over a ~120W combined load on +3.3V and +5V would cause the PSU to shut down. That left ~480W to find just from +12V. Will only 36A, that's impossible. The supply only managed to add another 340W to that 120W imposed limit using the +12V rails, stopping at 460W. Dropping back off of the 120W combined load to see if +12V could go further than around ~28A showed no extra headroom. Just over 27A combined is all the PSU can do.

It seems that the 600W quoted is merely a short-burst peak power. No amount of adjustment could persuade the supply to output more. At 460W efficiency was high and it wasn't very hot, but it didn't make the output power it claimed to be able to do, so it was classed as a failure. The supplied EPS to P4&P4+ convertor is a nice touch.

This may make me look at Thermaltake PSU's over Enermax PSU's for my next upgrade

[MercuryFree]

This may make me look at Thermaltake PSU's over Enermax PSU's for my next upgrade Heh, did they test the Thermaltake 680W one with FIFTY-TWO AMPS OF DOOM on the 12V? I'd be quite suprised if that could live up to it's claims.

I'm not an enermax fanboy really I'm not.

[swiftynz]

Shows how quickly things change - this guide needs an overhaul.

I still recommend the 420W and 480W Enermax models though, I honestly don't think you can do better for the money right now.

[zarathrustra]

Seems they didn't touch on the better Enermax Liberty Series.

[swiftynz]

Now having actually read the article I'd like to make a few comments.

Firstly it's old... 7 months is a long time in computer-land, and I'm pretty sure I read it last year.

The Thermaltake Pure Power-480APD is typical of older thermaltake power supplies, and reading the comments in the article will support my reasons for avoiding them. It was marked as passed despite delivering erratic voltages at high load, and erratic volages will kill your components pretty quickly. Sudden power loss is a much better symptom than unexplainable hardware death. It's interesting that the newer models appear to be a lot better though, and this will be reflected in a future revision. However when you look at the price of them they still don't make good value.

The Enermax power supplies clearly switched themselves off at a certain load level, and were marked as failures because they switched off before getting to their maximum rated output power (fair enough). However other power supplies that did make their maximum load clearly did not do so in a satisfactory fashion, yet were marked as passed. I don't know about you, but I'd rather my PSU switched of at 450W rather than continuing on to 500W and getting too hot to touch (ie FSP 500W). A PSU that allows itself to get that hot is not going to last long, and is quite likely to go out in spectacular fashion. For the record I like FSP PSUs, but that particular PSU clearly needs some kind of overheating protection.

Regarding the 130W limit on 3.3+5V, no normal system is going to get close to that figure.

The reviewer also seems to believe that 12V1 + 12V2 equals total 12V output power which is false. The sticker on my Enermax 420W supports that too - 12V1 is 18A, 12V2 is 18A, yet there is a rating for 12V total of 29A - still plenty for almost any system, but a far cry from 36A. It's disappointing that the reviewer missed this, as it is a common point of confusion for PSU buyers.

On the whole it is disappointing that the marketing departments are getting away with slapping high numbers on the box, but that Hexus article has too many flaws to be taken seriously. For example the "voltage rail variance" graphs were only averages, making them practically useless. It's fluctuating and ripple voltages that kill hardware, not slightly higher solid ones.

[Bung]

From the Hexus review
" you can see why sites like ours will harp on at you time and time again that it's not the output power rating of the PSU you should be caring about most. It's the connector options that suit your system, quality of output given and the purchase of a quality PSU from a reputable vendor."

yet the reviewer seems to use meeting the claimed output power rating as the basis for Pass or Fail. Who runs a PSU on the ragged edge?

[oD1Nz]

--snipped (I typed this while doing other things and don't want to repeat Swiftynz's excellent post)--

While I believe that things will have changed from then, I'm by no means an Enermax fanboy - I just think they're far better reliability wise than something like a Thermaltake.

Perhaps worth mentioning the Liberty series (http://www.jonnyguru.com/PSU/ELT620AWT/ELT620AWT.html) are very capable PSUs if you feel like paying for the quality.

[IronH]

The reviewer also seems to believe that 12V1 + 12V2 equals total 12V output power which is false. The sticker on my Enermax 420W supports that too - 12V1 is 18A, 12V2 is 18A, yet there is a rating for 12V total of 29A - still plenty for almost any system, but a far cry from 36A. It's disappointing that the reviewer missed this, as it is a common point of confusion for PSU buyers.


well this review here (http://www.systemcooling.com/enermax_eg701-02.html) also says the 600W noisetaker specification says it has a combined +12V1 & +12V2 output of 35A. I also did a search on enermax's website and they don't list the noisetaker 600W anymore (IA replaced by liberty and noisetakerII) however, even the 485W noisetaker (http://www.enermax.com.tw/english/product_Display1.asp?PrID=22) has a supposed combined 12V output of 32A, so it makes sense the 600W version should be able to do more?

PS thanks for pointing out the other stuff - eg systems not requiring more than 130W on combined 3.3V and 5V, and the fact the enermax's powered down vs continuing with fluctuating voltage like the thermaltake 480W did.

PPS I know its an older article, but its still relevant as the noisetaker and purepower PSUs are still available, and the noisetakers are regularly recommended here on these forums

Perhaps worth mentioning the Liberty series are very capable PSUs if you feel like paying for the quality.

yes the reviews on them are good (http://www.systemcooling.com/enermax_liberty_400-01.html). (the 400W versions aren't very expensive either.) I think I'll go for one of these.

Heh, did they test the Thermaltake 680W one with FIFTY-TWO AMPS OF DOOM on the 12A? I'd be quite suprised if that could live up to it's claims.

I assume you mean 12V not 12A? found this review of a Tt 680W purepower (http://www.systemcooling.com/thermaltake_pp_680-01.html) - only had 15A on +12V1, 15A on +12V2, & 8A on +12V3, haven't seen any with 52A claims, got any links? BTW this review wasn't so good.


PS - not a fanboy of anything, just wanted to throw in some critical thinking and discussion. No offence to anyone :cool: and glad there are those in the know who can point out any discrepancies/errors in these reviews. peace

edit - yet the reviewer seems to use meeting the claimed output power rating as the basis for Pass or Fail. Who runs a PSU on the ragged edge?

this was a review to see how they live up to their rated claims and so you know how much head room you have to play with, they have to test on the ragged edge. how else do you put a PSU through its paces? use a 500MHz system? :p

[MercuryFree]

I assume you mean 12V not 12A? found this review of a Tt 680W purepower (http://www.systemcooling.com/thermaltake_pp_680-01.html) - only had 15A on +12V1, 15A on +12V2, & 8A on +12V3, haven't seen any with 52A claims, got any links? BTW this review wasn't so good. Hmmm yes, yes I did. *edits*

And Straight from the horses mouth (http://www.thermaltake.com/product/Power/PurePower/w0049/w0049.asp), so to speak.
http://www.thermaltake.com/product/Power/PurePower/w0049/+w49_image/12Voutput.gif

[IronH]

zomg!! thermaltake suck

[swiftynz]

Liberty looks like a great PSU. They're pretty expensive though, and not much more powerful than the much cheaper noisetakers.

TT680W with 52A at 12V... lol. Clearly they have completely independant engineering and marketing departments.
Makes it hard to recommend them when the models varies so much within a given wattage range.

[oD1Nz]

New Noisetaker, the Enermax Noisetaker II (Rev. 2.2) (http://www.silentpcreview.com/article610-page1.html).

...the NoiseTaker is in need of more than just cosmetic changes to bring it up to current standards. We hope to see a NoiseTaker III with better quality fans and a low-noise fan controller. Until then, there are better (and much cheaper) options than the NoiseTaker II.

[sharp but blunt]

Liberty looks like a great PSU. They're pretty expensive though, and not much more powerful than the much cheaper noisetakers.

Just got the 400w Liberty it is realy awsome, love not haveing to use the cables if i don't need them and it's realy easy on the ears. but it was a bit pricey but you get what you payfor. and they look reay good if only i had a side window to show it off :(

[swiftynz]

New Noisetaker, the Enermax Noisetaker II (Rev. 2.2) (http://www.silentpcreview.com/article610-page1.html).Fair comments in that review. Somebody really needs to start importing seasonic in decent quantities.

[Azazel]

Fair comments in that review. Somebody really needs to start importing seasonic in decent quantities.
Indeed. You can get them, forgotten who from (mentioned elsewhere in here, IIRC), but they don't seem to have a dedicated importer.

For the record, my second Silverstone PSU (405 or somesuch) is going well and was pretty darn reasonable in price, to the tune of about $100. SPCR reviewed its bigger brother and had mostly nice things to say about it, with a few downsides. I'd be inclined to agree. Not a world-beater, but very good value and high efficiency (no heat problems here, despite a fanswap for a nexus @ 7V).

Speaking of SPCR and PSUs, I want a picoPSU and a high-power brick! Maybe a passive 12V meanwell psu... Oh, the SFF possibilities!

[Azazel]

For those interested, there's somebody's rough (and I mean rough) guide to brand reliablity. Not gospel, but interesting and perhaps useful to a few of us. Funny how the same brands always seem to show up ;)

http://www.jonnyguru.com/ratethebrands.html

[Pistol_Friendly]

hey guys, im not sure if this has been asked somewhere else, so excuse me :)

would my current Silverstone 400Watt PSU be ok for a AM2 system running these specs..

A64 X2 3800+
1GB DDR2-750 Kingston RAM
GeForce 7900GT

if not i may look into getting a enermax 500watt psu :)

[Azazel]

hey guys, im not sure if this has been asked somewhere else, so excuse me :)

would my current Silverstone 400Watt PSU be ok for a AM2 system running these specs..

A64 X2 3800+
1GB DDR2-750 Kingston RAM
GeForce 7900GT

if not i may look into getting a enermax 500watt psu :)
No problem whatsoever. I have a 400W silverstone running an OCed opteron 170, OCed 7900GT & 2Gb ram. It won't even be breaking a sweat. I'd estimate total DC power draw on your system to be ~150W fully loaded. It'd be one hell of an overclock to blow 400 on that. The only system that I can think of off the top of my head that exceeds that for sure is the fully kitted-out pentium D system that THG overclocked to 4.1GHz. Of course they boosted the voltage through the roof for that max oc, 4GHz would be the limit of your PSU with that system.

Short answer: No A64 system will overpower a good 400W psu except in really exceptional circumstances.

[MercuryFree]

Short answer: No A64 system will overpower a good 400W psu except in really exceptional circumstances.
Heh such as quad sli methinks

[Pistol_Friendly]

thanks azazel :)

[Azazel]

Heh such as quad sli methinks
Methinks not. From this anandtech (http://anandtech.com/video/showdoc.aspx?i=2769&p=3) article, which measures power draw at the socket, a specced up machine with a 7950 GX2 draws less load power than a single X1900XTX, meaning crossfire would be the biggest power draw. Even that is a mere 276W at the wall, or ~220W DC. Do the math and you'll still struggle to blow that power envelope. Sure you can if you like, but you'd sure have to try. A peltier would do it on its own, as would pumping lots of volts into your processor and XTXs, but like I said, you'd have to be trying.

For the record, the first aftermarket PSU I bought was 500W, then a 420, a 650 and now a 400. I've never gotten close to the limits of any of them, even with some huge overclocks and volt-modding.

[bigal_nz]

Has anyone, as a result of a PSU being underrated, ever seen a CPU cooling fan temporarily stop for 2-3 seconds during post messages at boot?

I have been getting some BSOD's and it seems to only be when I have lots of "extras" plugged in.

Cheers

-Al

[Shadow]

Heard about but not seen personally. It could be a bad connection somewhere.
Like a loose wire/plug that doesn't like being moved when you plug your "extras" in.

Haha, that reminded me of a funny story about a friend and his girlfriend.
She complains that the computer makes too much noise.
He rips out the dying case fan and goes to work.
She rings me up with "it reboots when I tilt the computer to the right".
I tell her "thats bad, don't tilt, use the lappy and I'll be around tomorrow to fix it".
Well the brainless wonder wanted to demo the problem to her friends.
So, ten minutes later I get another call...

When I got there the look on their faces was priceless.
Apparently there was a loud bang, followed by smoke and an odd smell.
Turns out, he had a replacement fan but it was plugless.
Being late for work he left the wires hanging, quote "who the hell tilts computers?".
Happened a couple years ago but still makes me laugh. Only the dvd drive survived, lol.

[That lol was for you whetu, being on the end of a sentence and all.]

[swiftynz]

Has anyone, as a result of a PSU being underrated, ever seen a CPU cooling fan temporarily stop for 2-3 seconds during post messages at boot?

I have been getting some BSOD's and it seems to only be when I have lots of "extras" plugged in.

Cheers

-AlThe CPU fan stopping during post is more likely to be due to a bios fan controller than lack of power.

The blue screens could quite easily be caused by an underpowered PSU, although I doubt the CPU fan stopping is a symptom. Make a new thread and troubleshooting with your full computer specs and the specs of your PSU if you want any further assistance.

[OtterFox]

thanks so much guys!! i just learnt about everything i know about PSUs from here!! :)

[farns]

Dual-Rail FAQ, SilentPCReview.com, Sept 2005 (http://forums.silentpcreview.com/viewtopic.php?t=23916)

[farns]

OCAU's PSU Wiki (http://www.overclockers.com.au/wiki/Power_Supply_Unit)

Awesome link that ^^, note that Thermaltake TOUGHPOWERS (not their other models) are a good PSU, right up with the others in the 80% efficiency class for quality. The 750w Toughpower is probably the cheapest option around for super-high-end as well.

[swiftynz]

Wow, some great info in that wiki, makes this thread somewhat redundant.
(Hint: go there!)

[farns]

Nah its all good, we can use it to keep track of good value PSUs on NZ pricing if nothing else. This excellent thread helped many n00bs inc myself

Best Enermax pricing seems to be www.computerlounge.co.nz while they and www.ascent.co.nz both have good Toughpower prices, www.c1com.co.nz has cheap Silverstones.

Good buys currently look like pretty much any Enermax or Silverstone, the Thermaltake Toughpowers (avoid the 550w tho) are just as good quality afaik but look a safer bet for ultra high-end rigs due to their quad-rails (see OCAU wiki or SPCR)

Enermax Noisetakers are cheap but only have a single PCI-E connector.
Enermax Liberty has modular cables.
Silverstone ST405 400w has lower efficiency than the others so if you can stretch an extra $50 for the 500w ST50EF its a gruntier and better quality PSU.

For a super-quiet PSU the Antec NeoHe or Seasonic S12 series are very nearly inaudible while having much higher +12v rail output than a fanless PSU. They are pricier than the above but far cheaper than a similar specced fanless PSU.
Be wary of using them in low-power systems such as a HTPC as they may need a decent loading to start up (see OCAU wiki or SPCR)

If Ive got anything wrong then pls advise :o

[Crazyhorse]

BUMP....awesome thread. Found via Google looking for Seasonic psu, one of the best!!

[The Spooner]

Very Useful, Thanks

[Azazel]

Very Useful, Thanks

Holy thread resurrection, batman! And from somebody with a laptop in their sig...

[swiftynz]

I appreciate the comment, but this thread is so dated now it's almost worthless... I'd strongly recommend you check out some other sources for info, such as the OCAU wiki linked in the first post. It was last updated July 2007, so it's far more current than the information in this thread.

This thread is #2 Google.co.nz ranked for "PSU guide", so perhaps I should put a larger message at the top....

[Crazyhorse]

This thread is #2 Google.co.nz ranked for "PSU guide", so perhaps I should put a larger message at the top....


Well maybe we should breathe some more liFe into this. Its still helpful Swifty. ;)