|From the model number, it appears to be an ECS/Elitegroup PM800-M2:|
I'll have to assume you have DDR400. I just downloaded the manual for the above & read thru the BIOS chapter. Your system is definitely overclockable. Start with just a minor/safe increase. Currently the CPU is running at 16 x 200MHz frequency. Try it at 206MHz...that will put the CPU at 3.3GHz. For this minor boost, all you need to do is adjust a couple of settings...the higher you go, the more complicated it becomes.
Enter the BIOS & go to Frequency/Voltage Control:
Spread Spectrum = disabled
CPU Clock = 206MHz
Save & exit.