Graphics card help!!!!!

[harishs]

Hello,
I have decided to buy a 450 Watts PSU for my a6120in computer replacing the existing 300 Watts PSU since i have bought a GeForce 8600 GT.I would like to know what things i must consider (like how much supply my present motherboard and other hardwares derive and what voltage split etc).Please help me as i am deperate to try out the new card.

Thanks in advance for the help !