^ so not true ;D
Guess who's chips are in the XboxOne and PS4. AMDs
I have owned 15 ati / AMD cards, and around 10 from Nvidia, and they are both great, with Nvidia normally getting a few fps more, and AMD delivering a better overall package
I have the smaller R9 380 8GB in my gaming PC and I am super happy with it. Plays the witcher 3 on high with some ultra settings at 40 fps. which is awesome for a 200 € card.
Should be more than enough for any VPX table.
Only thing is I remember the code of VP is optimized for Nvidia, but don't know if that still counts.
My cab uses an old nvidia 560 ti, and still manages to get 120 fps on VPX tables, but on full load.
So every 300€ + card should be very good, even may go for around 200€.
Edit: just read the above posts.
3 screens from a single card does perform better, because the cards don't have to communicate and share bandwidth across the motherboard etc. which helps performance on a multi screen setup. You also avoid micro stutter, which is sometimes more annoying than low fps.
Also switching to a standard OS instead of server might help. Key for good performance is to have the latest directX and openGL runtimes and latest graphics cards drivers, don't know if all of this is available for win server.