I’m running Rhino at work on an Nvidia GTX 285, hardly a fast card. At home I’m using a GT120, and have no redraw speed issues whatsoever. Both of these cards are ancient. While I have a pair of GTX970’s in 2 different MP’s, they are only used for CUDA rendering.
I would think whatever current gen laptop you get with ANY GPU would thoroughly clean the clocks of either of my cards.
Being as Apple doesn’t even offer a decent selection of GPU’s, you’re pretty much stuck with the R9 as your only option and that’s only on 1 model. Macbook “Pro” my ass. There’s hardly anything pro about it these days. They’ve crippled it by nuking all the ports, yanking the PCI Express slot and leaving you nothing but thunderbolt.
Support for 1080p resolution at up to 60Hz
Support for 3840-by-2160 resolution at 30Hz
Support for 4096-by-2160 resolution at 24Hz
24Hz? Really? Ever looked at a 4K display at 30Hz? It’s miserable.
There is one other option you could consider. You could go the EGPU route over TB. MacVidCards has figured out a way of running a desktop card in a TB to PCI expander and are selling the solution to those with new Mac Pro’s that are stuck with the Radeon D300’s and need access to CUDA as OSX’s openCL implementation is pretty weak sauce.
When I get some time I’ll break out my barge (old 17" MacBook Pro) and see how it holds up with Rhino. My guess is it’s probably fine.