I recently came across an older socket 939 amd 3800x2, 2 gigs of ddr 400 memory, pci x slot and all. Problem is I plan to build a new media pc for my brother as a wedding present, and my original idea was to use a am3 regor 240, with 2 gigs of ddr3 1300, and an ati 5750 or similar.
Question is, how big of a bottleneck if any would the cpu be if i used the old 3800? It would be used for medium ish gaming and movies, so the gpu is of importance.
I'm have that set up as a secondary HTPC running Windows XP MCE2005. For a TV Tuner, I'm using an ATI All-In-Wonder X1800XL. I'm not having any problems with it. It should run modest games fairly well when paired with a mid-range graphic card. I'd say nothing above an 8800GS/9600GSO or maybe the HD4670, otherwise you start running the risk of a CPU bottleneck.
(Note: I was running an 8800GTS-640 with an X2-4800+)