Mac Pro compatible graphics cards?

What graphics cards are Rhino for Mac group users finding a good choice at $1K or less?
I’m looking at the NVIDIA GeForce GTX 680
Running Rhino for Windows and Bootcamp. Looking for Nvidia CUDA card so I can evaluate Octane.

Have a looks at this:

I’m using an NVIDIA GTX 660Ti 2048 MB on MacPro 2008 and it’s working great, both on OSX and Windows.

In case helpful to someone, I chose two GTX 680’s (mac edition) for Rhino5 and Octane through Bootcamp on a Mac Pro 5,1.
Initially I was unable to get Windows to boot with both cards installed. The solution: connect 27" LED Cinema to the display port of the SECOND card.

I had a mac flashed 4 GB 680. While it did give a boot screen and was EFI compliant, it had some VRAM issues, and would crash on extended renderers in Blender (I’m doing all my final renders in Blender’s Cycles renderer, as it’s node based and I can get my head around that from a shader programming perspective).

At any rate, it was roughly a bit more twice as fast as a CPU only render.

I sent that card back for the aforementioned crashing issues, dropped a stock GT120 card in slot 4 on my cMP, and dropped a EVGA SuperClocked GTX970 in. That card renders at about 60% of the time it took the 680 to render the same frame.

So I’m going to put a second GTX 970 in, and my guess is even with the dual GPU overhead in blender (about a %15 hit) the two cards will render over twice as fast as the single 680, and 9X faster than CPU alone. I’ve still got the GT120 to handle my monitors, and the bennie of having a boot screen to deal with the OS X security updates which are perpetually breaking the NVIDIA Web Drivers. After watching power consumption over several multi day long renders on the single 970 I’m pretty comfortable with a pair of them running off the cMP’s power supply.

This too me was a good fit in the bang for the buck category. Granted I could get a single GTX 980 which would clobber the 970, but I can buy a pair of 970’s which will more than clobber a single 980 for about $70 more than the cost of a single 980.

While the titan x would smoke both a pair of 970’s or a single 980, it’s just not worth it in the price / performance dept, and it’s dangerously close to pulling more than the cMP’s PSU can deliver, so not worth messing with at this point.