Kind've new at this stuff, does the 12v count all 3 of the 12v abc together? Will this run the GTX 550 ti, thanks in advance .
You should be fine if your PSU has a 6 pin PCIe power connector and it's on a different rail than the 24 pin MB connector, which it probably is if you have the connector. Is your PSU rated for 500 or 550 watts? that's what I'm assuming from your voltages/amperages list here. You should be fine if you have the 6 pin PCIe connector.
The power supply's label should also have stated:
MAX. COMBINED POWER ON +12VA&+12VB&+12VC is 385W
Using Ohm's Law (i = P/E)you get a maximum combined +12 Volt continuous current rating of 32 Amps.
Since that PSU also has two 6-pin PCI-E Supplementary Power Connectors it is more than sufficient to power your system configuration with a single GeForce GTX 550 Ti.
thanks, its 460W, gotta upgrade soon but sort've broke and yes it has 2 6 pin connecter