If you have the first core generation of the FX series of cpu.
Then you will find when trying to overclock the chip, that you will get very little overclocking potential out of it.
The older FX series yours being a FX 8100 were known to run very hot when you tried to overclock them EJRONAN.
Some only managed a 100Mhz to 200Mhz overclock on the cpu with a large jump in cpu core voltage required.
Here's a link for proof.
http://
If I had to be honest with you, and you want a decent overclock of the cpu.
Then you should swap the FX 8100 series cpu for a FX8300 series that has a Vishera core update.
With a water cooling loop on the cpu, and provided you have a good motherboard with a AMD 990FX chip set on it you can reach an overclock of about 900Mhz over the cpu`s factory default speed in Mhz.