Intel Core i5 2500K OC @ 4.0 GHz Voltage?

[General Kenobi]

I've recently ordered a Core i5 2500K (for the rest of the build, see here), and I'm planning on overclocking it to 4.0 GHz for daily use with a CM Hyper 212 EVO as the cooling solution.

I'm going to be setting the voltage manually (obviously), and I'd like to spare some time and find out at which voltage I should start testing the OC for stability. Basically a maximum voltage that would be required for this overclock.... I'll start dropping it from there and see where it stops being stable.

 

[Diogenes2]

Actually just leaving everything on auto after setting the multi to 40, should work just fine.
Then use a negative voltage off-set, to lower the voltage until stability is established.

That way when you are at idle, the voltage will drop below 1.0 ..

The max will probably be in the 1.2 to 1.25 range if you have an average chip..

 

[General Kenobi]

Hm... that could work. I've seen people with chips that went up to something like 1.3 or low 1.40s though.

 

[fastamdman]

4.5 usually takes between 1.3 and 1.4 volts, generally averages to 1.35 prolly.

 

[gevorg]

for just 4.0GHz, your voltage should be under 1.30

as posted above, start at auto and see what voltages are being used, then manually try lower voltages and test for stability

 

[Idontcare]

Of course YMMV, and not sure how well 2600K Vcc's track with 2500K Vcc's (gotta be close though, I imagine), here's the min Vcc for LinX stability with my 2600K:

Now minimum Vcc will be dependent on your operating temps, so expect to need higher voltages if your cooling is less efficient (the curve above is for a lapped H100).

 

[Don Karnage]

My last 2500K before going 3930K needed 1.185v to run 4.0Ghz.

 

[guskline]

I have one 2500k running at 4400 (44 x100) and one at 4532 (44 x 103) and both voltages are auto. Personally, I've run every diagnostic known to man and they are solid. With this CPU and only OC to 4.0 Ghz stay at Auto.

 

[Diogenes2]

But the question remains, what are your voltages when left on auto ?
Most motherboards ramp up much higher than needed for stability.

At 4.5g, chances are it's 1.4v or more..

 

[Apoplexy]

I've got my 2500k voltage set at 1.37 for 4.5 GHz. You shouldn't have to bump it too much if at all for 4.0 GHz.

 

[BallaTheFeared]

Pressing the OC button should get you to 4.2-4.3 GHz.

Every chip is different, it's hard to say.

Best to start low then work your way up though, and 4Ghz isn't much of an OC for these chips.

You should start with stock voltage at most, then work your way up or down based on what happens.

 

[fastamdman]

Skip 4ghz and go straight to 4.5ghz. Set your vcore to 1.35, see if you are stable with linx for 2hrs and watch temps. If you are, drop down to 1.34, then 1.33, and so forth. If not, up it by .01 until you are. 4.5ghz will be anywhere from 1.3 to 1.4vcore which is safe as long as temps are within reason

 

[nyker96]

I see lots people clock it to 4.2ghz using just default volts. I think at 4.0 you can even undervolt a bit.

 

[Maximilian]

Ive gotten 4.2ghz with -0.020v offset and LLC fully off. It hovers between 1.26 and 1.27 in the BIOS and under prime seems to use around 1.25ish.

So yeah under 1.3v for 4ghz for sure.

 

[General Kenobi]

Thanks for the replies, I've got some idea on where to start now.

 

[guskline]

I did a little experiment with my licensed version of AIDA 64 diagnostic program. Monitored the CPU core temp readings at idle sufing the web and also when using their own stability program which stresses the cpu. The temps ranged from 1.00 for idle surfing to 1.336 for stress. That range is with my machine manually OC to 4400 (44 x 100) but with voltage settings on AUTO.
This is on my Asrock rig below. With my Asus rig OC to 4532 (44 x103) and cpu vcore settings on Auto the range was from .932 to 1.352 (idle to full stress). Hope that helps.