What power does my psu really supply

Hi

I have a huntkey 550w greenpower, does it really supply 550w or less, I want to add a second Radeon 5770, but that will depend on how much power I have to work with, the psu is rated at 80+ Bronze. Please advise

Current Specs: Amd phenom2 965, 2*2GB Kingston 1333, Radeon 5770 1gb ddr5, 5oogb 1tb and 1.5tb seagate HDD's, std 22* dvd writer, raidmax Quantum case,

Also how do I tell if my processer is c3 stepping or not ie it draws 130w or 140w

Thank you for your support and time

I wouldn't
http://www.hardwaresecrets.com/article/668

any advice on the processor question?

Here are the official ATI power supply requirements for the ATI Radeon HD 5770 and 5750 video cards:


450 Watt or greater power supply with one 75 watt, 6-pin PCI Express® power connector recommended

600 Watt or greater power supply with two 75 watt, 6-pin PCI Express® power connectors for ATI CrossFireX™ technology in dual mode


The recommendations are for an entire pc system.

Corsair and Seasonic are two brands that have a reputation for high quality power supplies that consistently earn high marks in technical reviews. They are reliable, stable, and come with a 5 year warranty. Some of the newer models come with a 7 year warranty (in the USA).