Radeon X1950 123.6W 10.3 AMPS
I don't think you will find the CX500 under
AMD Certified Power Supplies
support.amd.com/.../listing.aspx
The CPU uses 12v rails as well thats where ATX 12v comes from.
EPS 12V Guarantees the current on each 12v Rail.
500W is the TOTAL Power output. This means you can't have your cake and eat it too.
If you are using 130W on the 3.3v and 5V rails then total output is 370W for everything else.
Take away 25W for the -12v and the 5VSB. That leaves 345W or 28.75 Amps for the 12v Rails. Take away 8 amps for the 12v regulator that goes to the motherboard for the 1.5v power. This leaves 249 Watts of 12v power at 20.75 amps. So Radeon X1950 123.6W 10.3 AMPS is probably ok but its pushing things to the limit. If you add a 2nd hard drive or more cooling fans I would say you are over the top and it will fail or worse never turn on.
http://www.corsair.com/en/media/cms/manual/CX_English.pdf
If the max power was allowed on all rails based on this sticker it would be a 563W power supply.
Watts = volts X Amps 12 Volts x 56 Amps = 672 Watts and we know that this is not possible.
38 AMPS X 12 Volts = 456 Watts of a 500Watt power supply.
34 AMPS X 12 Volts = 408 Watts of a 500 Watt Power supply.
