Short answer- no.
Long answer, one or two of the 550W power supplies out there may run a GTX 480 but you will really be pushing them. I'd aim for at least 600W. You can get a good deal on one of the best 750W's on the market, a pc power and cooling silencer 750W, its recertified, but the price you cannot argue with:
http://www.directron.com/s75qbb.html
I have this PSU, and it's a very good, solid PSU that will be able to run what you need and also be "futureproof" to some degree as previously mentioned.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139006
The other positive is that the main 12 volt power supply is all on one rail so you don't have to worry about overloading the PSU by not balancing the system components properly.
Is this possible to run GeForce GTX 480 with a 550W power supply?
BTW, my GTX 275 worked fine with 440W power supply, not the recommended 500W![]()
I have this PSU, and it's a very good, solid PSU that will be able to run what you need and also be "futureproof" to some degree as previously mentioned.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139006
The other positive is that the main 12 volt power supply is all on one rail so you don't have to worry about overloading the PSU by not balancing the system components properly.