GPU Workflow

V-Ray V-Ray GPU General
1

I have been using Vray since 2006 and have had dual core Xeon machines the entire time.

Over time my hardware knowledge has not kept up. I spoke to Boxx and they quoted an i9-9900K with an NVIDIA GeForce RTX 2080TI 11GB. I’m replacing (or adding to my renderfarm) my current workstation that is a dual core E5-2620v3 @2.4ghz. Boxx’s push is - things are going to GPU rendering - which I haven’t really used since my current hardware couldn’t handle it.

I have several concerns - biggest is going back to a single core processor.

My main question - is GPU the way I need to start looking at things. My work is in the architectural field. Projects can be something as simple as a small convenience store or a 22 plex movie theater with a retail space in front - interior and exterior. Can GPU produce final renderings? Guess I’m looking for a little guidance before investing in something. The dual core option that was quoted was twice as much as the i9 machine.

Thank you in advance,

2

If you are going for GPU rendering, it will be best to invest in at least 2 GPUs in a machine with decent (not high end) processor. No need for dual processor or high end units in it - a 4 cores / 8 threads will be enough to not be a bottleneck for up to 4 nice GPUs.

Sure.

Will the GPU workflow suit your needs? The best thing here is to buy one 2080 Ti (or whatever you are planning to use in the future) and put it in your current machine and try rendering some of your previous projects.

3

Hi,
i got another question, maybe concerning this topic.

How does Rendertime scale with the number of graphic cards?

Expecting that one machine with 1 CPU and 1 Graphic Card needs for example 100 sec for a frame.

Does a machine with 1 CPU and 4 Grapphic Cards just need 25 sec for a frame?

I hope it’s clear what I am talking about. Thanks for reply.

4

Depends on the scene and the render settings. Progressive sampler should scale fine with 2 cards, but if you want better scaling with more than 2 cards (and machines) you should go for the bucket sampler in V-Ray GPU.

5

Okay this is quite theoretical.

So let’s use the bucket render mode for GPU rendering and expect a scene that is optimal for GPU rendering.

Would the rendertime for one frame be 4 times faster with 4 graphic cards of the same modell, than with just 1 graphic card?

6

It might be. I don’t think me or anyone else can promise homogeneous scaling across all scenes in the world.

7

Thanks you helped me a lot!

8

@TubeSmokeGuy Using 7x 1080tis at office with Vray GPU, and 3x 1080tis in my personal machine
Rendering speed does scale perfectly with more cards you add, for my case, rendering with all 7 GPUs is 7 times faster than rendering with one card
One case that this could be different is rendering animations, but there is a way around it
Say you have couple thousand frames to render, each frame takes 50 seconds on one card, in this case you will not get 100% scaling on all other cards, because rendering is so fast that your cards will be waiting for the scene to load into VRAM for each frame..
So what you do in this case is using Vray standalone, you can render one frame per each card, so in my case I will be rendering 7 frames every 50 seconds, and my cards will be always busy(not waiting for the scene to load into VRAM)
but for majority of your rendering, you should expect near 100% scaling with multiple GPUs

9

and yes GPU can do final rendering, I’m mainly using Vray GPU for all my work
Many other people do, see here,
andrematos

Everything in these links are rendered on Vray GPU

10

I am an old timer and new to the GPU work, I personally would fear to jump in the deep end. I am going to try GPU for my interiors, however, there are some limitations. I think I can get around these for my interiors, but not yet for my exteriors. I would hate to get stuck and not being able to render on GPU and not having CPU’s to fall back on. Plus, you do have a hybrid mode.