Recently, I just build my own rig using i7-2600k cpu, Gigabyte Z68X-UD7-B3 motherboard, 4x4GB Corsair Vengeance 1600mhz CL9 memory 9-9-9-24, gigabyte GTX 590 graphic card and two vertex 3 240gb solid state drives. I'm a newbie on overclocking issue, but managed to overclock it to 5.0ghz following some online guide but it is not stable at all after running intel burn-in test and prime95. To get stable speed, I have to somewhat lower it down to 4.4ghz. Although it passes the prime95 test for 8 hours of run, it fails the intel burn-in test (v2.5.1) at 'very high' stress setting mode. It passes the 'standard' and 'high' stress setting though. My current stable speed for workstation and gaming use is about 4.3ghz maximum. I read somewhere online that there many who can get the i7-2600k cpu to run stable at 4.8ghz using similar system and same cpu stressing softwares. For mine, it can't get past 4.4 ghz. Is 4.3ghz is the limit stable speed for my cpu ? Any expert overclockers here care to give me some advice on how to tweak the system to get higher stable speed. I have disabled turbo boost and LLC and set everything else to 'AUTO' mode.