Today I decided to OC my old 2600K a little bit more, since it was not quite keeping up with my GTX 970 in some games. Previously I had OC'd it to 4.1 Ghz (was running fine for more than 5 years). I decided to clock it more, however my mobo only allows me to do x42 multiplier, so to make it 4.4 Ghz I had to raise my base 100 Mhz to 105 Mhz (105x42). It also clocked my DDR3 to 1400 from 1333. I have all voltages set to Auto for both CPU and RAM. Everything runs fine, did even some burnout and performance tests, everything perfectly stable, no crashes.
However when I try to set the base to 106 Mhz for example, my PC wont boot at all and after 3 failed attempts to boot it says it cannot run because of recent overclocking and resets my OC settings. How is it possible that such a small increase in clock made my PC unable to boot ? From what I have read most people first get system instability (BSOD etc.) and not directly unbootable system when increasing clocks step by step.
My friend has 2600K also and he is able to clock it up to 4.9 Ghz with all voltage settings set to Auto as well. I know that chips may vary in quality ... but such a huge difference ? My passmark score is 9700, my friend is able to make 11 000 score in the same test. So 10% more performance just from that 0.5 Ghz extra clock.
Temperatures are below 60C when my CPU is on 4.4, I have the biggest noctua air cooler with 2 fans and large passive part, so heating is not a problem at all so I feel it might be able to run at least at 4.6 or so.
Thanks for any ideas and tips.