I have an HP Pavilion Media Center m8430f. Here are the specs: Intel Core2 Quad CPU Q6600@ 2.40GHz 4GB RAM NVIDIA GeForce 8500GT Windows 7 64-bit OS 300W PSU I purchased an Antec Earthwatts 750W PSU (still uninstalled) and now I need to know the best graphic card I can put use. I've read so many reviews and heard opinions through the roof and am unsure which way to proceed. I need to keep my budget around $275. I've read a LOT about overheating, room in the case etc and I am at a loss. The graphic cards I have been looking at are the BFG NVIDIA GeForce GTX 275 OC 896MB, the XFX ATI Radeon HD 4890 1GB DDR5 and the BFG NVIDIA GeForce 9800GT 1GB GDDR3. Any help would be greatly appreciated! Thank you.
With the new PSU you can run about anything, that case is plenty large enough for anything except the 5970 (which is outside your budget anyway)
I would probably suggest a 5770 instead of the 4890, since the 4890 is the last of its generation. Either the 5770 or the GTX275 would be a good board.
From the picture of the case I don't see any issues with space, at most you might need to put a stronger case fan in. (also if you can get a GPU that exhausts out the back of the PC then do so, but it isn't mandatory)
I upgraded Gateway and Dell PCs videocards regularly before I started building my own rigs. I did not even have to change power supplies in most cases.