In my main editing station I have a 3GB VRam Sapphire AMD Radeon HD 7950, which works OK with FCPX. It's barely adequate with Premiere though, meaning I can playback almost in real time, almost all the time, in HD at 1/2 resolution (no rendering.)
I tried to playback my current Premiere project with the stock 1GB Radeon card... LOL, it's a disaster! Nothing plays! Playback is terrible no matter what I do, 1/4 resolution, everything tuned off, no go! The screen doesn't even update when I park the cursor further down the timeline. Terrible!
Boy, the Sapphire is an expensive card, and I only have one of them... What if it craps out? And really I would need an even better card to playback at full res in PP. But what's out there?
According to MacVidCards: Nvidia GTX 780 6GB ($525) or Nvidia GTX 980 Ti 6 GB ($660)
or Nvidia GTX Titan X 12 GB Maxwell (for a cool $1099.) Pretty limited choice.
Some vendors have flashed cards on eBay. Some 3GB and 4GB cards for a decent price - Like this macvmotive or this lonestarmacpro. Are these cards any good? Do they work fine with editing apps? I need to do some research. I'm not very found of eBay though.
In addition... Nvidia or Radeon?