questions about overclocking!!

[utopian201]

Hi all
Are there any motherboards that let you increase the memory speed, but leave the pci bus at 33Mhz?
Cos when you oc the memory, the pci bus is increased as well, unless the motherboard supports a particular fsb pci divider right?

If so, where can I find information on what speeds a motherboard supports??

I doubt this will get answered, since no one goes to this part of the forum, but if i put it in the general forum, it woulda been moved here
:P

[Humantuckshop]

The basics of dividers: 1/4 = 133 Mhz FSB and a 33MHz PCI bus, 1/5 = 166MHz FSB and a 33MHz PCI bus, and 1/6 = 200MHz FSB and a 33MHz PCI bus.

All the KT333 boards have the 1/5 divider. The only board I know of with the 1/6 divider is the Iwill XP333.

[mird-OC]

aside from dividers the HumanTuckshop mentioned, there is so such thing as a fixed PCI bus.

fixed PCI buses have been a rare thing in the last few years. back in the day of the 6x86, some SiS chipsets had a fixed PCI bus setting, so you could run your FSB at 75MHz or 83MHz and keep your PCI bus in spec. i'm not entirely sure why the idea was abandonded, but maybe it had something to do with the benefits of OC'ing the PCI bus as well. of course there are probably some latency issues when running a fixed PCI bus instead of using the dividers.

AFAIK the i845x P4 chipset supports a fixed PCI function which is interesting (the latest BIOS for the Abit BD7 mobo implements this feature)... maybe it's time for it to become a bit more mainstream.

other than the i845x chipset, i don't think there have been any other chipsets made recently that support such a function (probably because of aforementioned latency issues).