I was wondering if the video card/graphics card XFX ATI Radeon HD 5750 would be compatible in my Dell Dimension 8400? Also what card would be most recommended for the best gaming in my computer for around the same price as the ATI Radeon HD 5750?
the real issue is your CPU. it's not fast enough for the 5750. you would not see a difference between the 5750 and 5670. In fact I doubt any card above the ATI 4670 would show you any major FPS increase.
a cheap ATI 4650 DDR3 or 4670 would give you some extra FPS but the reality is your PC is too outdated for modern games. The only fix would be a new motherboard, CPU, RAM, video card, and case (basically a new system) I assume you own a copy if Win7 since XP comes installed on that DELL.
I just put a Sapphire Radeon HD 5670 in my Dimension 8400. I bought it because it was a steal at $65. The card replaces an x300. And, the new card nearly brought the 8400 to its knees.
I downloaded the latest drivers and Catalyst Control Center (CCC). Then I ran the "auto-tune" in the CCC and I got the dreaded blue screen of death. I rebooted and manually adjusted the graphics options. I haven't had a problem since then, although I haven't done much with the card yet; I've only streamed online video from ESPN3 and Netflix. The video looked great, the sound came through the HDMI cable, and I was happy.
As long as you don't run any other programs, this card can work in a Dimension 8400, but you'll notice the bottleneck immediately and you'll want to significantly upgrade the rest of the system -- merely moving from a 3.0ghz to a 3.2ghz Pentium isn't going to help. I plan to wait for AMD to announce their new processors for 2011, then I'll make a decision about an AMD or Intel motherboard/cpu combo from Newegg.