What GPUs for killer Octane workstation?

#1

I’m a mac guy that will be buying parts for a DIY PC this week. Previously I was shopping for render nodes but decided instead to upgrade my primary workstation.

Since I’ll still need to render at times using CPUs I’m going for the 8 core i7-5960X.

I plan to buy it initially with just 1 GPU, but in a few months add two more.

Looking for beefier cards. Thoughts?

So far options look like this:
Option A: Titan Black 2880 Cuda Cores / 6 GIG / $1050 (1 now/ 2 later)
Option B: GTX 780 TI 2880 Cuda Cores / 6GB / $900 for 6GB version (1 now; 2 later)
Option C: 970s 1664 CUDA / 4GB / $350 (3 now)
Option D: Buy 2 GTX 980 2048 CUDA /$600/ 4GB (2 now; 1 later)

#2

A or D, it depends if they sorted out the problem of slow rendering on the 9xx series yet. Id veer towards A.

#3

Thanks for your reply, imashination. I had heard about disappointing tests on the 9xx that might–or might not be resolved through updated drivers.