Watchdog workaround 2 video cards

Accelerated Computing CUDA CUDA Programming and Performance
1

Having only one x16 PCI-Express slot is it possible to use an old PCI video card (not nvidia) as primary display? Will it work as workaround for the 5s limit or will i need to buy a new motherboard?
Thanks

2

If you’re using Linux, then this should work fine.

3

What about under XP?

Thanks again