Can you teach my step by step on how to overclock? What settings to choose and what not?
This might help.
http://apcmag.com/overclocking-101-our-step-by-step-guide-to-maximising-your-pcs-speed.htm?page=1
Disable all of the following settings:
Speedstep (EIST)
Turbo Mode
C1E
C-states
For i5 users, change your voltages to the following settings:
CPU Vcore (CPU Voltage) = 1.35V
CPU QPI/VTT Voltage = 1.3V
Your memory speed is determined by multiplying the base clock by the memory system multiplier, while the QPI speed is similarly set by multiplying the QPI clock ratio by the base clock.
So as you increase your base clock to increase your CPU frequency, you must also lower your QPI multiplier and memory multiplier, to ensure your QPI and memory stay within their normal operating speeds:
Base clock
We're going to aim for a conservative 3.6GHz overclock first. Find your CPU multiplier value, and then divide 3,600 by it. This should leave you with the target base clock. For example, our i5 750 CPU has a CPU multiplier of 20x. Divide 3,600 by 20 and we're left with a value of 180, so we set our base clock value to 180MHz.
QPI
Set this to its lowest possible value, which is usually 32x. Lowering this has no discernible impact on performance, but having a higher QPI setting will stop your overclock from working.
Memory multiplier (also known as memory ratio, memory frequency or DRAM frequency)
Drop this so that when it's multiplied by your new base clock, your final memory speed is equal to or lower than the speed your DDR memory is rated to. For example, if you're running DDR3 1,333MHz memory, you'd want your overall memory speed to be no higher than 1,333MHz, so you'd set your multiplier to 6.
Make sure you have a decent cooler though.