Hello, I hope there's a guru out there somewhere that can help me. I've just recently upgraded my PC with an Asus P8P67 PRO motherboard and Intel Core i5-2500K 3.30GHz together with a Noctua NH-C14 cooler. The installation went very smoothly and I thought I'd try out the Auto Tuning/Overclocking utility. This increases the multiplier and checks for stability and using this I was able to reach 5047MHz, it looks like it will go higher, but I stopped the utility at this point. My temperatures are OK, but in order to do this it pushes the Vcore to over 1.5v which is a bit high. I also read that the AI tuning utility has a tendency to overdo the Vcore and that you can generally achieve a similar overclock with a lower Vcore voltage. I like the idea of keeping SpeedStep enabled, so that when the CPU isn't being stressed the system throttles back to around 1600MHz and lowers the Vcore to around 1.2v. I tried adjusting the ATV, Additional Turbo Voltage, setting in the BIOS, but it didn't seem to have an effect. Is there a way I can use the Auto Tuning function and keep all the nice power saving functions, but set a lower Vcore limit for the Turbo function?
The CPU will be quite happy to overclock while keeping the speed step enabled. Although, achieving 5GHz with anything under 1.4v might be optimistic, but not impossible. On average, an overclock of 4.5GHz is achievable with approx 1.32v ish. But of course, every chip is different you may do better. This is a really useful guide and worth a read http://hardforum.com/showthread.php?t=1578110
Thanks bdigital, I had come across that article before, but I had a re-read and made some adjustments. Using the TurboV utility, I was able to increase the mulitiplier by one without increasing the voltage over what the Auto Tuning utility had set for 4532MHz - 103x44, meaning I can get 4635Mhz - 103x45 with the same voltage, keeping it below 1.4v at full load, running Prime95. It will go faster still, and although the auto tuning utility is a little bit over zealous with the Vcore setting, it seems that you do have to increase the Vcore significantly to push it to 5GHz. All in all though, I'm pretty pleased with a 1.3GHz overclock with air cooling, which although not completely silent, is pretty quiet, considerably quieter than my previous water cooled set-up in fact.
