I've been looking to upgrade from my old nVidia 7600 GS to something better, but I have a rather low-end PSU. It's a Thermaltake 430 Watt with a single 12V rail providing 18 amps. It's currently powering 2 sticks of DDR2 Ram, 1 DVD Burner, a 500 GB 7200 RPM Samsung Spinpoint HD, Intel C2D E6600 2.4 Ghz, two 80mm fans, and one 120 mm fan.
So basically my question is --> What's the best possible card that will perform well given an 18 amp 12V rail?
I'd rather not a buy a new PSU as I'm just looking to get better performance in Source games like TF2/L4D/HL2/CSS.
A 9800GT. I had the same PSU for about a year, I was able to run my 9800GT, and then my HD 3850 without issue. However, once I got my HD 4850, it barely gave enough power to turn on, yet alone be stable.
Try to get one of the Hybrid Power ones, which will put less stress on the PSU.