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View Full Version : Overclocking my e8400 - vcore, vtt & temps


Chakka
05-14-2008, 01:20 PM
I had my new rig up and running for the past few days and Im running prime95 for stability. Im safely at 8x500= 4ghz with mem running 1:1 at ddr2 1000 and 5,5,5,15 2T - but!

I have to set my vcore at 1.39375v in bios and vtt at 1.3v, vdroops to 1.376v idle and 1.36v load to get 24 hour prime95 stability. My temps are 34c idle and peaked at 60c load. I have seen others get better results with lower vcore but I dont see many of them testing like I do...I ran 1 p95 test for 12 hours and again 1 more for 24 - set my vcore 1 notch lower it bombed twice after about 8 hours p95. Heck, I can go 9x500 for 4.5 ghz but I have to bump vcore up to 1.45v (didnt even try to check for stability)

I decided to try something different. Im running 9x400=3.6ghz right now with mem 1:1 at ddr2 800 and 4,4,4,12 2T at the following:
vcore at 1.3v and vtt at 1.2v, vdroops to 1.28v idle and 1.264v load.....what is amazing is that my idle temp is still about the same at 32c-33c, but my load temp hit a high of only 50c so far and p95 testing I normally see the temps hover between 46c-48c.

What is amazing is that for .1 less in vcore, my temps drop by 10c at load...thats a big difference imo. I know that heat (not vcore) will kill chips and chipsets...if you had this choice, what would most of you guys do, run higher at 4ghz (feels good to pound my chest) or go with 3.6ghz (I will try to lower vcore later but this is my first stability test at 3.6 ghz)?

srpeters18
05-14-2008, 04:50 PM
Higher than recommended max vcore can over time damage your processor regardless of heat. But you are correct in your thinking that heat is the fastest killer of CPU's. But 60c is not too bad, especially after 12+ hours of prime95. 60c shouldn't hurt it.

Limbo
05-14-2008, 06:06 PM
What are you using to measure temps Chakka? I found serious discrepancies between CoreTemp and what was in the BIOS, I tried numerous programs and RealTemp seemed to be closest to what might be true. I trust none of them with my E8400 though.

Congrats on the sweet overclock!

Chakka
05-14-2008, 10:32 PM
What are you using to measure temps Chakka? I found serious discrepancies between CoreTemp and what was in the BIOS, I tried numerous programs and RealTemp seemed to be closest to what might be true. I trust none of them with my E8400 though.

Congrats on the sweet overclock!

Yes I use realtemp. I read through the whole thread at extremesystems and the guy who wrote the program is a "real" genius. For those of you who are interested, the thread regarding temps with these new penryns is here:

http://www.xtremesystems.org/forums/showthread.php?t=179044

Btw Limbo, Ive read your thread about your e8400 - are those overclocks stable with prime95? Or are you just trying to see how far you can take you e8400?

Limbo
05-15-2008, 06:33 AM
I've never tried to see what the highest I could get it to boot at but those speeds were just for the benchmarks I was running. I never spent days doing fine tweaking, I don't have the patience.

For stability testing it passed easy at 4095 MHz @1.33V in BIOS, CPU-z says 1.33V, on air with the TRUE. RAM at 1092MHz effective, 5-5-5-15

I used OCCT, http://www.ocbase.com/perestroika_en/index.php?Download to test stability and RealTemp showed 32C idle, 49C full load with ambient at 21C. My cores are always witin a degree of each other temp wise. I have a good case which seems to work really well for cooling.