Want to overclock my 2600K beyond 4.5GHz. Where to start?

[Anusha]

Hi guys,

So I have a 2600K running at 4.5GHz with 1.320V (I'm using offset +0.065) and is dead stable. Recently I bought Silver Arrow SB-E Extreme cooler and was wondering if it will allow me to clock it to 4.6GHz or even 4.7GHz. 4.8GHz would be awesome. But I want to be realistic.

Right now, the room temp is a bit high (27C) because it is closing in on Summer and Prime95 (with AVX) reaches 75C on the hottest core after a while. This is with the fans at 1100RPM. Fans @ 2500RPM drops the temps by another 4C.

Here's general information
・I am currently using manual volts for everything, and lowest volts at that.
・The motherboard is ASRock Z68 Extreme4 with latest beta bios that enabled Ultra Fast Boot for Windows 8.
・I have every power saving feature turned ON.
・I want to use Offset mode. But I guess I can enable that after finding the correct VCore.
・I am using LLC level 4 (level 1 is highest and level 5 is lowest or OFF) because if I go higher, the CPU gets BSODs at idle. I guess it is a problem with the motherboard? Maybe the implementation is buggy.
・Spread spectrum disabled

Here are the other voltages
・I have 4 RAM sticks running at 1600MHz, 9/9/9/24/1T with just 1.35V.
・CPU PLL is set to lowest: 1.586V (PLL overvoltage OFF)
・Additional Turbo Voltage: +0.004
・Everything else at AUTO

With these settings, 4.6GHz isn't ｓtable.

Sorry, I cannot provide the screenshots of the BIOS settings because I am not at home at the moment.
Ask away anything you want to know.

Where should I start? Please help. I don't want to do any unnecessary things. That's why I wanna here for you guys.

・Increase the VCore?
・How long should I stress test before I move on to the next speed?
・Which stress testing app should I use? Prime95? IBT? AIDA64?

 

[theDTP]

Hi, this is how I was running my 2500k for 9 months after 3 months of trial and error and some of the differences between our setup.

I didn't have every power saving feature turned on despite what has been said about them having no affect on overclocking, I had C1E/EIST disabled, also I didn't have voltage offset. PLL voltage wasn't changed so I assume it was 1.8v, VCCIO was 1.1v, ram was at 1.5V.

To put in short, my CPU ran at 1.42V and 4.8GHz every second it was turned on with maximum stress temperatures being 71c, so a lot lower during other tasks, I used 1.52v (this is the max voltage to be used on a SB processor) for 5.1GHz benchmarks with the temperature hitting 85c.

Remember with the majority CPU's there comes a point where going over a certain speed suddenly requires more voltage per MHz. For example on my 2500k:
1.2v for 4.2GHz
1.28v for 4.5GHz
1.3v for 4.6GHz
BUT 4.7GHz required 1.4v
THEN only an extra 0.02v for another 100MHz so that being 1.42v.
So, this "point" for me as you can see was 4.7GHz requiring an extra 0.1v for only 100MHz but I was happy as my temperatures stayed "low"

Stressing to check temperatures I used prime95 and OCCT, for stability I used real world tests such as going about my daily computing life and if I run in to any problems then take necessary steps to rectify as there was many of times in the first 3-4 weeks of getting my 2500k where I'd stress for hours on end and it was "stable" but then BSOD while performing a task I've performed 100's of times that week, so even though it was stable in stress tests it was only 99% stable in real world computing. Hence why I had 3 months of trial and error but it paid off for me as I was able to run 4.8GHz daily and have decent temperatures and allowed me to bench at 5.1GHz.

My suggestion to you would be to increase the Vcore to get 4.6GHz. That "point" I talked about could be here for you and require only really small adjustments to achieve beyond 4.6GHz. You may need 1.4v for 4.6GHz to break that barrier but then need no further adjustments to voltage for say 4.7GHz, 4.8GHz. Remember, keep those temperatures and volts safe.

 

[Anusha]

Those maximum stress temperatures are reached when stressed by which app? Prime95 Blend? Prime95 Small FFT? 71C is pretty sweet, but that is at which room temperature? See, now being almost the summer here in Japan, the room temps are hitting high 20's. Today it almost hit 30C. This is inside the apartment, not outside.

 

[theDTP]

Large FFT, room temp was low around 22c.

 

[Anusha]

Large FFT, room temp was low around 22c.

Thanks