Render on 6 Core Processor

[diogodasilva@mac.com]

Hello,

I just recently upgraded my machine and am now running on an intel i7 980x .. 6x 3.33 ...

I am running windows 7 64bit.

I have noticed while rendering a scene that the CPU usage never goes beyond 35-40% ...

Is there anyway I could make use of the full CPU power?

Thanks in advance..

[dkendig]

Re: Render on 6 Core Processor

there isn't a setting you can set that will effect this, no.

[stevebo]

Re: Render on 6 Core Processor

Is this limited by Sketchup or Vray?

[dkendig]

Re: Render on 6 Core Processor

it shouldn't be limited at all by either, so it's really hard to say. Either way, you guys can't change a setting in our program to "fix" it.

[edonk]

Re: Render on 6 Core Processor

Doesnt the light cache "passes" setting achieve this dkendig?
If I stick this setting to "8" it uses all 8 of my cores at 100%.

[dkendig]

Re: Render on 6 Core Processor

No, that value isn't designed to control the amount of your cpu that is used.

Documentation on Light Cache

Number of passes - the light cache is computed in several passes, which are then combined into the final light cache. Each pass is rendered in a separate thread independently of the other passes. This ensures that the light cache is consistent across computers with different number of CPUs. In general, a light cache computed with smaller number of passes may be less noisy than a light cache computed with more passes, for the same number of samples; however small number of passes cannot be distributed effectively across several threads. For single-processor non-hyperthreading machines, the number of passes can be set to 1 for best results.

There isn't a CPU throttling option of any sort, that's what I was trying to say. If certain values being set, make v-ray use more cpu than other values, it's should only be because the render is more complicated. At least as far as I know. The only thing that would really make any difference for cpu usage would be the low thread priority option in the Global Switches. That should really only effect performance when you are multitasking though.

[edonk]

Re: Render on 6 Core Processor

Hmmm if I remember correctly, if I set my passes number to less than 8, then I get a warning in the info box that all 8 cpus arent being used.
So in theory what number should I actually have in the passes for an 8 core cpu?

[dkendig]

Re: Render on 6 Core Processor

Your guess is as good as mine. All I know is that V-Ray should be taking advantage of as much CPU horsepower as it possibly can, so there shouldn't be a setting that allows you to control how much CPU is being used, because it should be using as much as possible whenever it can. Fernando might have a better answer for you, he's our trainer.

[OzBoz]

Re: Render on 6 Core Processor

As far as I know Sketchup it self is still just single core. That's pretty stupid but doesn't affect rendering with V-Ray. V-Ray uses 100% overhere. If I remember correctly from a tutorial the number of passes should be equal to your number of cores. But I can't remember where I heard it.

[fpedrogo]

Re: Render on 6 Core Processor

Hmmm if I remember correctly, if I set my passes number to less than 8, then I get a warning in the info box that all 8 cpus arent being used.
So in theory what number should I actually have in the passes for an 8 core cpu?

You should use the number of how many core you have in your PC

This is what number of passes does. Y
Number of passes - the light cache is computed in several passes, which are then combined into the final light cache. Each pass is rendered in a separate thread independently of the other passes. This ensures that the light cache is consistent across computers with different number of CPUs. In general, a light cache computed with smaller number of passes may be less noisy than a light cache computed with more passes, for the same number of samples; however small number of passes cannot be distributed effectively across several threads. For single-processor non-hyperthreading machines, the number of passes can be set to 1 for best results.

[dkendig]

Re: Render on 6 Core Processor

is the cpu not being fully utilized during other parts of the render, other than during the light cache calculation?

[thomthom]

Re: Render on 6 Core Processor

Should use all cores during IR and DMC. Least what it does on my quad-cores.