I5-2500k overclocking (voltage help)

Spaminator92

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Aug 29, 2011
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Hello all.

I have an Asrock P67 Pro3 and wanted to overclock my I5.
I tried to do this by using one of the standard OC'ing options in the bios (lowest was 4Ghz - used that one) however Windows didn't recognize that OC.

Set it back to default settings and used the 'AsRock eXtreme Tuner' software to overclock. I increased the CPU ratio 3 times to x36.

That shouldn't have been a problem, but I ran prime95 anyway. After about 5 hours temperature was stable at 60°C (Using a Scythe Mugen 2).

I noticed the core voltage in CPU-Z was around 1.32V though, which I found rather high for this ratio. (I had only changed the ratio, left everything else on default.)

So I went back to the Asrock software and found the option "CPU Voltage Offset" I changed this from 0 to -0,010 V and that dropped the voltage to about 1.224 under 100% load. The temperature under load is now quite consistent at 53°C, big change, innit?


So right now my question is if I should keep on lowering the voltage offset (because lower voltage, while remaining stable, is better, right?) or perhaps raise the ratio a bit more.

Maybe some guidelines of what temp/voltage I should be aiming for would be handy :)


AO11V.jpg


Prime 95 running for 17ish hours. Lowered the voltage 5-6 hours in.
 
You could never run prime95 that long if your voltages were off at all, but to simply run 3600mhz it can be done completely on auto, if you're satisfied at 3600mhz and that's your goal to run lower temps at your set voltage, then bravo and kudos to you.

With every Intel feature enabled even 53c would have throttled back on you, which means you're not actually running all 4 cores at 3600mhz anyway, it's just an illusion.

Run CPU-Z while running Prime95 and watch the multiplier throttle back when your temperatures increase.

If you want to really overclock the 2500K you need to get away from the automatic overclocking, and overclock through the BIOS, but first you need to learn what you are doing.

However if you're satisfied running 3600mhz then congratulations, You're There!

There are guides here to help you, if you want to go further.
 

Spaminator92

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Aug 29, 2011
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Well, I sat it all back to the default settings and then increased the ratio (and later decreased the voltage). I'd be fine with a higher OC, if I can run it on lower/same voltage and about the same temps.

I was running CPU-Z the whole time, and while running prime95 it was on the max multiplier (x36) the whole time..
 

BE4TNUT

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Jun 24, 2011
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Just as a reference I OC'ed my 2500K to 4.4ghz with stock voltages - actually I think I had it at 1.3 vcore on that run, overclocking while half asleep is not recommended and makes recall details a little fuzzy haha - and also running a noctua nh-d14 cooler and getting low 30's at idle and 58 under load. I have not ran P95 for more than 1.5 hours though.
 

Spaminator92

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I've ran Prime95 for 3 hours now, at 4.0Ghz (actually less, since the bus speed is 99.8 according to CPU-z?) and it seems to be stable, 100% load at 53°C.

Voltage of ~1.19, offset is -0.175V though. Quite large, but only the final number matters, right? Or am I wrong here...

I could probably drop down the voltage a bit more too. Should I do that?