Sapphire HD 7750

Might be. Can't really know for sure, but it's likely. Depends on model, though. And your specs  .

my specs. as follows:

CPU: Core-i3 540
MOBO: Gigabyte GA-H55M-S2
RAM: Corsair Vengeance 1600mhz 8gb(2x4)
GPU: Sapphire HD 7750
HDD: Samsung 1tb
DVD-RW: LG lightscribe
USB: 3 devices

do i need to upgrade my psu, thinking of this one Corsair CMPSU-430CXV2UK or any other suggestion.

CX 430 would be nice. What is your current power supply unit? Specs would help.

PSU is 17A@+12V

Ouch. Even though it shouldn't hit that limit, but it might use up to 75% of the rated power. I could imagine it's close to this power supply unit limit. Even if it isn't the power supply issue, I'd suggest to upgrade it: having a cheapo PSU in your system is a risk, it could explode and take components with it.

thank god it didn't explode just restarted and working fine.

so CX 430 V2 would be fine to OC my cpu to 3.68 ghz with my current specs.

Best answer selected by Simu.