drop idle temps 7-12C using this tweak

[graysky]

Forget about using programs like CPUIdle, you can do this yourself with freeware utils. My idle temp lowered from 47C to 40C (chipset temp is 24C) just by using this; there is no negative impact to my GPU either according to sisoftsandra tests and the prime95 benchmark! I should note that this will only lower your idle temp, your full load temp will not change.

It activates the C1 function Athlon XP CPU's support. Most mainboard brands have this feature as an option in the bios you can enable and disable. I just found out that EPoX doesn't have that feature. So what you're doing is just using a direct reg tweak to activate it. It's not like you're forcing anything, the Athlon XP chips are made to support this feature so it shouldn't do any damage.
When the CPU is idle the mainboard will send a command to the CPU that will cause a part of the CPU to be deactivated (and therefore not produce any heat). That's why this tweak only works on the idle temp and doesn't change anything on the load temp. Ofcourse as soon as the CPU power is needed the deactivated part will become active again, so it should have any influence on the performance of the CPU.

Remember, this is for nForce 2 chipsets only. I found this by googling, "WPCRSET nforce2" so I suspect that if you google "WPCRSET <your chipset here>" you'll find the correct register to change for your chipset. I know for example that on my old Asus A7M266 board, the values where different.

Please reply to this thread with your results. Maybe some people out there with pCMark2004 or some other synthetic benchmark util can try this and report the results?

Anyway, I found the instructions here.

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...forgot to add this: if you want to read more of the APCI C1 and C2 modes built into AMD Athlon XP chips, read this document. Chapter 4 talks about the different modes [C1, stop grant, HLT, C2, etc.] which are there from AMD so they're safe to use!

[graysky]

...so is anyone else using this?

[lycorn]

Well, GIMPSters never have their processors idling, so there will be no real point in using the feature...
Thanks for the hint anyway, it is always good to learn new facts about PCs .

[graysky]

True... but not everyone runs p95 24/7. Info is good :)