I am looking to replace my flaky Geforce 210 in my linux mythbox (fedora 15) with a GT640. Intially, I tried to replace the 210 (I forget the manufacturer) with a Zotac 210 (with 1GB instead of 512MB that my old card had), I was unable to get any video output past the initial boot screens (i.e. when the actual desktop is supposed to appear). You'd think since it was the same 210 model, it would just work. No, regardless of compiling new drivers, beta drivers, etc... stick the old 210 card in and I'd get to the desktop.
So, as I look at GT640's, I see 1GB, 2GB, 4GB cards. I'm hesitant to just pick one from a random manufacturer without knowing if it will work after compiling new NVIDIA drivers. Is anyone actively using a GT640 in a linux machine? If so, which one?