What is the most productive video card to take in a computer with an E8400 processor?

Question

Video cards

The video card burned out in the computer, a budget 9500 GT was temporarily bought, now I want to buy the most productive video card and, if it makes sense, buy another 4 gigabytes of RAM. I don't see a full upgrade option.
Current computer configuration:
Processor: Intel Core2 Duo Processor E8400 (6M Cache, 3.00 GHz, 1333 MHz FSB)
Video card: NVIDIA GeForce 9500 GT
Motherboard: ASUS Rampage Formula
RAM: CORSAIR DOMINATOR TWIN2X4096-8500C5D DDR2 2x2GB, 1066
Cooler: Zalman CNPS9700
Power supply 600 watts.
Operating systems: Ubuntu and venda7 in dual boot.
The target resolution in games is 1920x1080, since a large TV set is used as a monitor and we are sitting quite close to it. It is also desirable that in the future the video card should have the highest possible performance if SteamOS is installed on the computer, I don’t know if it is possible to predict which video cards will be supported in terms of drivers at the moment.

Answer 1

The RAM would definitely be worth it, about the vidyahi - see the characteristics of the motherboard, and select what it will pull