E8500 Overclock

[DAD 2,650]

I may try the 3.8Ghz, too. But yesterday I was not successful when just setting the bus to 400 and leaving everything else as is; will try to fiddle with the core voltage though. which are your setting here? Tom, I see you are using 1.205v. I read somewhere that 1.35v might be needed? So should I start with the lower value? What is the default core voltage and which are the 'allowed' specifications for the E8500?

hm, just tried it w/o success. tried first 400*9.5 (9.5 being my highest multiplier, nothing higher is accepted) with 1.250v and then with 1.35v (or similar, my mobo just gives some weird presets different from the one I mentioned I read elsewhere). Both times the PC did not start. What else would I need to set? FSB strap is set to 333, DRAM freq to 800 (400*2), PCI freq to 100 and everything else is set on auto.thanksphil

[Guest Tom R]

To find out which revision your cpu is (c0 or e0) download "cpu-z". just google it and you'll find it. Once you do that, run it and take a look through all the tabs. It has a lot of info on whats connected to your mobo.As for me, CPU-Z shows 1.16V, however in the bios the Vcore is set to 1.205.I have my board at 400X9.5.. and i dont really know how to explain the ram.Still am pretty new to o/c'ing.i have a gigabyte EP45-UD3R.As far as intel.com shows...E0-Max temp is 74CMax Vcore is 1.3625C0-Max temp is 72CMax Vcore is 1.3625

[Guest Tom R]

interesting read. just oc'ed my e8500 yesterday for the first time. chose 380*9.5 so far, just adjusted the DRAM freq and nothing else. works at 3.6ghz like a charm, just 37C on both cores when running fsx with ASA and the PMDG MD11. Prime95 brought temps up to 70C though...I may try the 3.8Ghz, too. But yesterday I was not successful when just setting the bus to 400 and leaving everything else as is; will try to fiddle with the core voltage though. which are your setting here? Tom, I see you are using 1.205v. I read somewhere that 1.35v might be needed? So should I start with the lower value? What is the default core voltage and which are the 'allowed' specifications for the E8500?Besides, how do I know whether my E8500 is a E0 model? brPhil-E8500@3.6Ghz-8800GT-Asus P5E-VM HDMI-8GB Corsair-Vista64

BTW... always start default vcorethe way i did it, (took me about a half day)bump the FSB up by 5, save bios and restart.do this all the way until system is unstable (or doesnt start)keep the fsb at the last unstable numberadjust vcore till systtem starts and is stable. i think default is 1.18V? can anyone clarify?

[DAD 2,650]

BTW... always start default vcorethe way i did it, (took me about a half day)bump the FSB up by 5, save bios and restart.do this all the way until system is unstable (or doesnt start)keep the fsb at the last unstable numberadjust vcore till systtem starts and is stable. i think default is 1.18V? can anyone clarify?

Thanks, will give it a try later. So far I just downloaded CPU-Z... and wonder why the core speed differs. between 2280hz with multiplier 6.0 and 3600hz with multiplier 9.5... seems to be dependent on load. Is that normal?thxphil

[Guest Tom R]

Thanks, will give it a try later. So far I just downloaded CPU-Z... and wonder why the core speed differs. between 2280hz with multiplier 6.0 and 3600hz with multiplier 9.5... seems to be dependent on load. Is that normal?thxphil

That's actually an Intel feature. It reduces the CPU speed when the CPU is not needed much (i.e. idle)Normally for overclocking its turned off.I dont remember the name of this feature.... step up technolgy?cpu/2s or something like that.play around in your bios you should find it there.

[DAD 2,650]

play around in your bios you should find it there.

thanks. btw, I actually have a C0 version of the E8500...

[Mace 1,909]

Mine is at 1.45v. 430 @ 9.5. If I go lower my system becomes unstable and FS9 CTDs.

Chuck that seems to be a pretty high voltage for a Penryn but I know you are knowledgeable and so you probably know that already :)Have you tried 450 x 9 with say, 1.20-->1.30 or so volts? I've had more success dropping the mult to 9, personally.

[Chuck_B 2]

Chuck that seems to be a pretty high voltage for a Penryn but I know you are knowledgeable and so you probably know that already :)Have you tried 450 x 9 with say, 1.20-->1.30 or so volts? I've had more success dropping the mult to 9, personally.

Yeah, I have Mace. And I agree -- but it's the weirdest thing. Where I'm at seems to really be the sweet spot. I know I'm pushing enough voltage through there to light Chicago, but when I deviate from this setting too much it just seemed that I started to get instabilities. But I think I'll try again, now that I've got everything else to settle down. I've been pretty bored just flying lately anyway! Thanks for reminding me to look again! :-)

[Mace 1,909]

E0-Max temp is 74CMax Vcore is 1.3625C0-Max temp is 72CMax Vcore is 1.3625

I meant to ask you TomR, or any of you...is there any differences you know of between C0 and E0 other than the differences above?Mine is a C0, purchased in April 08.

[Guest Tom R]

I meant to ask you TomR, or any of you...is there any differences you know of between C0 and E0 other than the differences above?Mine is a C0, purchased in April 08.

I hear that the E0 is better for overclocking (runs a bit cooler).I dont understand the technology behind it. Perhaps someone can explain it....

[krishcanag 0]

MyMOBO is almost the same and my E8500 is running at 4.1GHz, with some voltage adjustments

[Mace 1,909]

MyMOBO is almost the same and my E8500 is running at 4.1GHz, with some voltage adjustments

Krish what voltage do you run for 4.1 ghz?, I am still experimenting with mine and would like more references...

[krishcanag 0]

CPU Core 1.36875 (CPU-Z shows 1.33

[Chuck_B 2]

Chuck that seems to be a pretty high voltage for a Penryn but I know you are knowledgeable and so you probably know that already :)Have you tried 450 x 9 with say, 1.20-->1.30 or so volts? I've had more success dropping the mult to 9, personally.

Mace: I wanted to thank you for kicking me in the pants and making me going back to tinker with this. As you suggested I moved the multiplier back to 9 and now I'm running around 440 and have been able to dial my voltage back to 1.35 (so far) with no apparent stability issues! My temps are now down a full 6 - 10^o C! I strongly suspect my earlier instability issues lie in my 'High Performance' RAM, which I now know needs to be UNDERclocked just a tad.I've been meaning to post for a few days now but have been so busy it' crazy -- thanks for getting me motivated to go back and try, try again!