VRay RT- GPU memory limitations?

[FaustoDeMartini]

Hello! I'm buying a new system and I would really appreciate some info so I can decide which way to go. I can either get dual Xeons with a lot of threads and lower GHz or a dual Xeon with a lower amount of threads and higher GHz (which is a cheaper processor). More threads is great for CPU render and higher GHz is great for GPU render from what I heard.



I'm doing some huge environments on the project I''m working on (which is reaching around 600 million polys- with all XRefs around 6GB file with quite of bit of textures) and I know that Vray CPU will render it but I'm not sure if vray GPU can handle that much data. If I go with a cheaper and higher GHz Xeon, I can put 4 Titan Xp's, otherwise I will have 4 1080Ti's (with the more threads Xeon). So to resume:

Dual Xeon E5 2697A v4+Four 1080Ti= More threads and geared towards CPU, but able to do good GPU render

Dual Xeon E5 2643 v4+ Four Titan Xp= More GHz and geared towards GPU render. Not a good choice for heavy CPU renders due to a low amount of Cores/Threads

A more technical comparison between the processors:

http://www.cpu-world.com/Compare/487...-2697A_v4.html



I tried to find documentation online about it but with no success. Do you guys have any insights in this matter?


Thanks so much!!!!


-Fausto.

[Alan Iglesias]

Hello Fausto,

In order to even consider GPU rendering for final production work the first thing you need to do is to determine whether or not current high-memory GPU cards can handle your "huge Environment" scenes. Hopefully, someone will chime in here about scenes of your size and you will be able to determine if someone here is rendering them successfully on the GPU. If not, then perhaps you can borrow a high-memory GPU card for testing.

Then of course, you need to be sure that GPU rendering will properly suit your rendering needs. RT/GPU has come a long way in the past few years but still does not support everything that Vray Advanced does. Some searches here and a look in the online docs should clear that up for you. For instance, if you are using Forest Pack materials for your environments then it would be a good idea to investigate the GPU's shortcomings in this regard.

If you come to the conclusion that GPU rendering is for you, then of course you'll want to put together a machine that is GPU-strong, but please remember that with Vray 3.6's Hybrid Rendering, you can now send GPU rendering data to the CPU(s) so your CPU speed and core count will be important as well.

Just a few things to consider before buying a machine...

-Alan

[FaustoDeMartini]

Hi Alan!!

Thanks so much for the time and attention! What I ended up doing is getting a middle ground Xeon that has a good GHz and amount of Cores/Thread. The processor I got is the Xeon E5 2687w v4:

http://ark.intel.com/products/91750/...Cache-3_00-GHz

I spoke to a few friends using different render engines (Octane, Redshift and Vray RT, although Redshift is able to leverage more system memory from what I heard) and that is the best solution I found. I hope this thread helps other people that are doing more and more GPU renders.

Thanks!

-Fausto.