Originally posted by: Denithor
Probably a fanless FX5200 or FX5500 is your best bet, there are a couple @ newegg for like $30 + shipping. Try to find one with 128-bit memory interface, it'll be slightly faster.
He said power consumption is most important, performance least important, so your recommendation is a GPU that was poor at both, then encourage a 128-bit interface for better performance (which also will consume slightly more power). Bad day for reading?
FX 5 Series is currently supported only under XP. W2000 drivers were retired but the final driver should be very stable. There are no Vista drivers except a BETA RC2 driver that will install on RTM and SP1 but may be buggy as hell.
Radeon 7000 ~ 9250 has been completely retired even for XP/2000, but the final driver should be very stable. Vista has XPDM drivers in-box that will provide basic function only.
Is this for Linux? You may want to go with Radeon 8500 ~ 9250. I seem to recall reading there are stable fully functioning open source drivers for ATI R200 (no missing, partial, or buggy feature support). I'm not sure about Radeon 7000, which is R100, not R200.
Not sure what NV chips have similarly good open source drivers. You can also find tools to edit the VGA BIOS for most GPUs and downclock the core/mem to reduce power consumption.