To EIST or not to EIST...

[dkm777]

...that is the question. Since one of the RAM sticks in my main rig decided to go south I'm currently stuck with my backup. It has an MSI P45-C51 mobo and a Core 2 Duo E8400. Currently I have it OCd to 4GHz (450x9, 1.366Vcore under load, 1,38Vcore while idle - no loadline callibration). But there's a catch - I absolutely have to disable all power saving features or it won't post even a hair over 400MHz FSB without insane amounts of Vcore (think 1,5V). Current overclock gives me a ridiculously snappy and satisfying performance and I'd hate to downclock it to levels usable with EIST. How's the power consumption on Wolfdales at such clocks? Is it worth using EIST?

 

[sm625]

I think you'd save about 20 watts with speedstep, and probably 10 more if you were forced to run at 400fsb. If you are idling for 6 hours a day with no EIST, then you're wasting about $5 per year on electricity, $10 at most. Even with EIST disabled, the cpu still pulls less power at idle than at load, even if the frequency doesnt change. So I would just leave it how it is.