Has anyone else encountered this problem? When rendering with MR (batch or normal) Maya only uses 25-30% CPU.
I’m using Maya 2014. i7 CPU and 18Gb RAM. Windows 8.1.
I have manually set the threads in batch render options to 8. Still, Maya only uses around 25% CPU (and 2Gb RAM, but it’s a fairly light scene).
Perhaps I should add some details about the scene, in case it has any relevance to the problem…
I have about 5.5 million polys. 2 area lights, with portal light and black body shader. Sampling is set to unified sampling at 0.7. And, an miss skin shader connected to mia_material. Renders with only mia_materials went unusually slow, but workable. It was after adding the sss-shader that I checked the system resources to see what’s going on. 2 hours in i’m still at 0%, and that’s only for a 1280 square. It really is painfully slow.
Seems a lightmap issue to me. Graph the sss shader with the hypershade and check the lightmap node parameters, and delete the expressions in the resolution boxes. Set up a resolution that is 50% of your render resolution and do a render test.
Do you have few high resolution models in the scene? Or are you rendering a lot of elements such as foliage?
Ideal settings vary for every computer, but in my experience with a machine with similar specs as yours, with 24 render threads you should be able to reach 100% cpu usage. Remember to disable “render on network machines”.
I assume you have turned on “progress messages” in the verbosity option of your render.
This level of reporting may help reveal the issue. Misss skin shader introduces the creation and usage of a subsurface scatter lightmap. Some parts of the preamble to beginning a render are not done with multiple threads. Once it actually starts rendering pixels you should see everything kick in.
The next level of verbosity “detailed messages” is a major dump of every event in the render process and this in-depth printout should uncover why its being so slow and perhaps why its not using all the threads on your machine.
By the way 5.5 million triangles is not what I would consider a “fairly light scene”.
I have similar problem like Redkatt, but no matter what I’m rendering, maya uses only 25-30% of resources.
I tried to disable “network rendering”, tried to set manually threads and memory that maya will use, but nothing spectacular happens.
No matter if I render 5.000 polys, or 5 millions polys, it still uses 25-30% of available hardware.
I tried with Mental Ray, V-Ray, but at the end result is the same.
Last night I was rendering still image, pretty simple scene, with maybe 3.000 ploys, little reflection on object and 4 lights, in 2k resolution, about 20-25 minutes?! I’m not talking about production quality setting in Mental Ray 
Also tried in V-Ray with Open GL, or Cuda, but it’s still slow.
Any idea why it’s so slow?
I’m working in maya 2014, on HP z400, quad xeon 3.2 ghz, Nvidia Quadro 2000 and 12 gb of ram, Windows 7 Pro 64-bit.
As some of you mentioned it was an “issue” with the lightmap. I first tried turning off “include indirect light”, and noticed CPU went up to 100% after building the lightmap (which was alot faster). And now I tried rendering with indirect light on, but changed the lightmap to 256x256 (512 square render). It completed in 36 minutes, whereas before I gave up after a few hours when nothing happened.
The whole lightmap thing is a major problem with multithreading. Having a lightmap really small will create bad flickering when in motion around smaller/thinner objects or small features.
As polygon counts go up, lightmaps become even more of a problem since it’s a rastarized calculation, not a raytraced one - meaning if the polygons are smaller than a pixel, it’ll take significantly longer.