Hi, I am new to overclocking and I decided to try my hand at it. The first thing I tried was using my motherboard's (Asus p8p67) AI Suite II auto tuning option to overclock. Apparently, I just pressed a button (the FAST option) and my computer restarted and showed me a message of 31% increase in performance at a clock speed of 4.2 Ghz. The stock speed is 3.3 ghz.
However, when I go into CPU-Z the core speed shows as 1648.9 mhz. The bus speed is 103.0 with a x16 multiplier. Now once in a while the multiplier jumps to X42 but it is really brief and it quickly goes back to normal. Why is this happening? I thought my CPU's clock speed would constantly stay at 4.2 Ghz?
I would appreciate any help with this. Thanks in advance
It is a power saving feature working as intended. It will stay at the lower state (notice the lower voltages) unless you do something that needs processing power and then it will go to the 4.2Ghz that you want it to be at. If you really want to disable that feature so that it is always at the higher speed you can do that in the BIOS.
Sandy Bridge CPUs were designed to have these features enabled so that the CPU uses less power when you don't need it at 100%. This "problem" as you call it actually isn't one. It can instantaneously switch to full clock speed when needed, like when you start up a game, and then immediately switch to low-power idle mode when you don't, like when you're browsing the web.
If you really want to have the clock speed stay up constantly, you have to disable C1E and all of the CStates settings also.