Multiplier puzzel

[Deviant]

This is a tough one, but I'm having strange results when overclocking this TBred-A.

It does 1979MHz stable @1.75V (12.5x158), will nearly boot into windows at over 2GHz, but needs more voltage but I'm not going to do that at this stage.

all multipliers work as it is factory unlocked.

The mobo does at least 174 MHz FSB as I've had it there.

I can do 1835MHz with 166FSB and multiplier of 11.

But when I go multiplier 11.5, which is only 1909 MHz it just wont post.

Mobo is Shuttle AK35GT2 KT133.

It's got me a bit puzzeled at the mo.

Has anyone had any problems like this before?

I'm going to see just how high I can get with 11.5 multiplier, and rip the heatsink off the northbridge to check the paste underneath next.

[Deviant]

Ok, it does 11.5x165 just fine, but 11.5x166 and no post. I'm thinking it's a BIOS problem. I'm going to email tech support, but feel free to make any suggestions.

[must kill Dell adguy]

maybe at 166FSB it automatically changes the PCI divisor or something???
AK35GT2???? I thought that had a KT333 Chipset???
I didn't know that KT133 could support T-Breds....just Palomino.

[mird-OC]

it uses the KT333 chipset, but the KT133 chipset does support tbreds... it's just board dependant (much like palomino support).

[Deviant]

Originally posted by must kill Dell adguy
maybe at 166FSB it automatically changes the PCI divisor or something???
AK35GT2???? I thought that had a KT333 Chipset???
I didn't know that KT133 could support T-Breds....just Palomino.

Typo sorry, it is a KT333 chipset. And I think you are onto something, and thinking the same as me. It's is doing something, or not doing something at the crossover to 166 FSB. It's funny how the mobo can run higher, the CPU and the memory, but it just doesn't like that particular multiplier/FSB combination. I have email tech support not that I expect anything from them, but it would be cool if they found something and did a BIOS update.

I want that multiplier/FSB ratio so I can a high FSB and high CPU speed but not overclock my PCI/AGP bus too much and damage/overheat my HDD.

[Deviant]

Woot, just got this TBred to run 2003 MHz with 1.78v

[Gronk the small]

2GHZ .. on an 1800xp.... what sort of cooling plant are you using? Liquid helium or what???

[Hans]

2GHz on a TBredA is very doable. (provided u got a good chip, of course). If you are on air cooling, it won't be quiet though. (not if you wana be cool as well.)

[Gronk the small]

Hmm, haven't tried to push mine That far .. but I think some further experimentation is in order !

[Tens0r]

for some reason i cant change the multipliers in bios on my a7n8x.
i can select them from the list but when i reboot with new settings it says 'cpu overspeed' and wont boot any further.

cuz otherwise im sure i could get this thing over 2ghz no problem.

[I.R]

Sounds like it's locked :confused:

[Tens0r]

but yea... a locked tbred on a a7n8x :(

and it is definatley a tbred because of the core size and stepping.
AIUGA

[Humantuckshop]

Well, it sounds like some T-Bred A's are locked and some are unlocked.....


We could start a thread to try and determine which ones are locked and which ones are unlocked. We could do this by owners of T-Bred A's looking at the stepping, colour of the CPU and week of manufacture.

[Deviant]

Originally posted by Hans
2GHz on a TBredA is very doable. (provided u got a good chip, of course). If you are on air cooling, it won't be quiet though. (not if you wana be cool as well.)

I can reach 2GHz with my volcano 9 on high (noisy), or slightly higer 2021MHz with my modified TAK68 (very quiet) so my modification is very impressive indeed.

[Deviant]

I've just solved my multiplier puzzel, it seems my mobo doesn't support a /5 pci divider.

When I run 166FSB my PCI=44 MHz and my AGP=83 MHz which was running nice and stable.

It seemed when I was going up to 168 FSB I would get crashes in games, and I got as high as 174 FSB which is a whopping 43.5 MHz PCI and 87 MHz AGP bus.

I am also running a sound blaster live so god knows how that can handle such a high overclock in these temps at the moment.

I'm going to email Shuttle and see if they can do a BIOS fix or else this mobo won't be able to support a XP2600+ or a XP2700+ 166 MHZ FSB versions.