So I have my 2500k running at 4.5 GHz and 1.35 V. I'm cooling it with a H100i (which is awesome, by the way) and it isn't touching 60 degrees Celsius at 100% load. I'm rather new to overclocking and was wondering how much farther I can push my cpu.
Here's some pics:
http://i.imgur.com/Br4ak.jpg
http://i.imgur.com/gtTLP.jpg
I know I didnt run Prime95 that long, but I had already tested it for 5 hours earlier and it never tocuhed 60.
Step one, run prime 95 for at least 12 hours to check if the overclock is stable, if so try bumping the multiplier up just a touch. Run prime 95 for anothr 12 hours, if stable repeat the process untill unstable or too hot, if not stable bump up the voltage a touch, run prime 95 (12 hours).
Do this until the max CPU temp reaches 80-85.
You MUST run prime 95 for at least 12 hours, an oerclock might fail straight away or after only two hours or after eight hours, you just never know.
Hard to say. It's more trial and error than anything. I have a 4.5GHz OC on 1.325v but I get toasty temps of about 67c on a Xigmatek Dark Knight. That's my everyday it's not summer OC. When summer rolls in, I dial it down to ~4.2GHz because my room gets hotter than the devil's asshole since it's on the second floor in direct sunlight with no AC.
If I were you, I'd ramp the voltage to 1.4 - 1.425v and see how far you can take it. You should be able to take it to 4.8 - 5.0GHz range with that voltage. My testing methodology is I fiddle around with benchmark "stable" which means it doesn't crash or fail within 15-20 minutes of Prime until I think I got a winner. I do this for two reasons: 1) So it doesn't take me several weeks to dial in an OC, and 2) to make sure temps are reasonable. If it's benchmark stable and temps are low, I dial up the clock speed, rinse, repeat. Once I think I have a promising setting, I do a 24 hour Prime95 blend or small FFT, depending if the OC affects my memory or not (shoudln't unless you mess with the base clock). Small FFT if you just want to stress the CPU. If it survives Small FFT for 24 hours without error, you have stable. If it doesn't, either dial up voltage, or turn down clocks. I'd lean towards the latter since higher voltage isn't good for the CPU's longevity. I'd stay under 1.45v
There are many schools of though in terms of stability, read the Prime95 readme file for more info. Personally, 24 hours or bust.
You should be able to get to at least 4.8Ghz, but not all 2500K CPUs will be able to get that high. I have heard of them getting up to 5Ghz or even 5.2Ghz before though. Your maximum safe voltage is going to be 1.5V (it actually might be more like 1.55V, but I don't remember), but I personally wouldn't go above 1.48V. You don't have to run Prime 95 for at least 12 hours every time you bump up the clock speed a bit. I would run it for about an hour each time you increased the clock speed until your system crashes. After that I would clock it back down to what it was before it crashed and then run it for at least 12 hours to make sure it's stable. Running it for 12 hours every single time you increase the clock speed is going to waste a lot of time, and I personally don't have the patience for it. I only test it for 12 hours once I feel like I've reached a clock speed I find acceptable with settings that I feel are stable. If they aren't stable then I increase the voltage and try again.
With my 2500k and my current 2600k I immediately set voltage to 1.5 and start at 5ghz and drop voltage until un stable. Then tweak everything else for 100% daily driven stability since I never turn my systems off.
bump it to 1.5v and the multi, run prime for minimum 12 hrs and just keep an eye on the stability. from what i have seen most 2500k's have best stability from 1.4-1.45 with a slight bump in the multi, but it seems like we've all touched on the volts and multi, hope we helped you