Power Supply needed for 6600GT?

[RCL66]

I'm looking to upgrade my video card to a Geforce 6600GT and was trying to find out if my 350W power supply is enough. I have been unable to find info on power requirements online. I have 2 DVD drives and 2 HD's in my current PC (also have a Geforce 5900XT currently)

 

[RCL66]

Thanks for the fast response! How much of a jump do you think the 6600GT will offer over the 5900XT? Esp with current tech games like HL2 or Battlefield 2 ?