I'm running a 680i based motherboard with an ATI X1900XT video card without issues. Before that it was a NF 570 based mobo. Never had any issues related to the video card and mobo not playing nice.
As Heidfirst already stated though, if you planned to do a crossfire setup with that X1950, it'd be an issue. You would need an ATI/AMD chipset for cross fire and an Nvidia chipset for SLI.