2500k on Asrock z68 pro3-m. I overclocked it to 4.2ghz : base 100 * 42. In the bios, it states that cpu voltage is 1.32, and I choose offset mode. I also choose whatever below that to +0.03v. In turbo boost power, I set them: short and long to the value of 250. I disable spread spectrum,cie, c3,c6, and thermal. When I log in window and open cpuz, its say cpu voltage is 1.36v at 4200mhz, then it came back to 1.008v when core speed is 1600mhz. I run prime 95 and core speed is 4200.5, 4200.6, 4199.8. cpu voltage when running prime95 is 1.304-1.296. no crash, no bluescreen. I have a question about voltage. why it is so diffrent, prime95 is lower that when first boot into window and lower in the bios. is the core speed when running prime 95 change below and above 4200 is not normal. is it not stable? Must it be 4200 all the time?