I want to overclock my processor to around 3 ghz but many people have told me that this power supply is already under supplying my components and I'd need at least 650 watt corsair with 48 amp min to go for overclocking. Is this right? It simply doesn't make sense though. What do you guys say?
Here is what the expert on techsupport forums said
"I have another suggestion which could be a reason your system is bottlenecking. Your silverstone power supply is not a very good make, it is also underpowering your system.
These days you should have a minimum 550w psu for any pcie graphics card and if you do plan to overclock with that psu you will certainly cause some damage. You should be running a good quality psu and you should be running a corsair 650TX especially if you plan to overclock."
EVGA's specifications call for a minimum of a 400PSU (Minimum recommended power supply with +12 Volt current rating of 22 Amps) with one 6-pin PCIe Connector. Your PSU meets those requirements (36 amps I believe). Where you can run into issues, is overclocking your PC can cause an increase in voltage and add in more components... etc. than you put a strain on your system. Looking at what you have listed, I don't see that really being the case for you.
Though I do agree a 550W power supply would provide better "safe" room but your power supply is capable of such a small overclock on your CPU and maintain your system.
As for the advice of a 650W Corsair, it is only true if you are going to be running an overclocked system with dual GTS 450's... I would agree that would be your safest option.