Hello I got a Dell Optiplex GX620 that is running Lubuntu(I plan on changing to a different distro). It has a Intel Pentium D running at 2.80GHz (no over clock), 4GB of RAM and a pitiful 250w PSU. Right away I upgraded the PSU to 500W (550W max) and I want to git a new graphics card. I need a graphics card that can play games like Gmod and Minecraft (in 720p) but I would like to know what the max graphics card I could install would be. I have no real price range, I don't think this rig could handle a card that cost $300.