Workstation GPU for 3D modeling, animation, etc.?

Question

Computers

Guys, I need help from experienced 3D designers and developers. I'm just getting started, so please be understanding and non-aggressive if questions are not asked correctly. In short:
Need a workstation for highly detailed:
Sculpting (Zbrush, blender)
Modeling / animation (maya, blender, modo)
Rendering in Cycles, Nuke , V-ray, Arnold very heavy scenes (immediately the question is: will 8 GB of GPU be enough for renders by layers or is it generally better to compose environments aimed at the CPU, and supporting only the CPU render, in order to send the scene to the render farm, instead of rendering on the GPU?) This question is not at all clear to me, and if you can tell me more , I will be very grateful.
Also, another problem in choosing a GPU:We can not decide on the GPU brand.
AMD - wins with OpenCL / Nvidia - with CUDA ( and viewport performance {2,0} ?!)
renderer, viewport?
As I understand it, the GPU is used mainly only for viewport performance and for some renderers (Cycles) , but it is not clear whether stream processors (AMD) perform the role of CUDA and whether there is a big difference between AMD and Nvidia (professional cards like FirePro/Quadro k)while working in the above workflows? And what are the pros and cons, if you had experience in this matter?
The choice is between Titan, Titan Z, GTX 980, FirePro W7100, r295x2 The
question of whether it is advisable to choose a card in the direction of consumer cards, instead of professional cards (firePro - quadro k5000) is also tormenting
If someone has experience, and if you have already encountered all problems of this kind, please share.

Answer 1

From my own experience, I can say that buying professional cards is throwing money away. For gaming, Nvidia releases more stable drivers and they have Cuda. AMD is cheaper and therefore more powerful for the same money. If it's not a pity to overpay a little, feel free to take 980 or Titan.

Answer 2

Tyts

Answer 3

For rendering on a processor (V-ray, Arnold), a powerful processor is important.
For rendering on a video card (Octane render), the video card is important. It is obvious.
From here you can understand where to invest.
If you are not going to render on a video card, then even the integrated graphics of the processor will be enough for simulation. With a competent scene structure, you can work with any volumes, hiding layers and objects from the view that are not required at the moment.
For comfortable work and smooth display in viewports, any new nvidia video card on the new architecture is suitable. Dual-processor cards (Titan Z, R9 295x2) in the viewport will work at half.
CUDA is actively used in many programs, OpenCL is rarely used.
In 3d modeling programs (3ds max, maya), quadro video cards are worse than gaming GTX. At the same cost, the quadro will be weaker. And specifically.
I worked on the built-in graphics with scenes where the plant is drawn to the bolts, you can work.
Now I have a Titan Z, but I took it to render on the GPU.
Choosing a video card by speed in octane rendering here: octane bench