Backburner Monitor showing incorrect CPU availability

[sebbiej]

http://knowledge.autodesk.com/suppor...les/Backburner...

Hi all,

I'm trying to get Backburner set up in our studio (as quickly as possible as we've got LOTS to render), but I'm having trouble with our render server. It's got 40 (hyperthreaded) cores, but backburner only sees 32 (in the queue monitor), and when it renders it only uses about 65% of the power available.

I found the above article on the Autodesk website, but it only gives help regarding Mental Ray, but we are rendering using Vray 3.0.

Is there a fix for this (preferably one where we don't have to type in some something in the Additional Options box everytime we want to render a scene!).

Many thanks.

Seb.

P.S. I posted this on the Autodesk forums, but somebody suggested posting up here, so thought I'd see if anyone can help here .

[ivaylo.ivanov]

The link seems not working. What is the fix for Mental Ray?

If I remember correctly 32 was the old limit of CPUs that XP for example supports. Then this limit was extended, but to preserve backward compatibility, Microsoft required additional steps to get CPUs above this limit. I guess you will not have this issue on Linux.

[sebbiej]

Hi Ivaylo,

Sorry, here's the correct link: http://knowledge.autodesk.com/suppor...ilability.html

Ah so that may be why it's not working, that's annoying!

In the above link it outlines:

Issue:
Without hyperthreading the Backburner Monitor is showing 20 CPUs which is correct. with Hyperthreading enabled it is only showing 32 when it should be showing 40.
Causes:
Backburner Monitor is incorrectly displaying the actual available CPUs.
Solution:
Go to Render > Create Backburner Job.
Set Render to "from the scene file".
In the "Additional Options" section put the following:
-mr:rt 40
Once the render is submitted notice that the machine uses the correct amount of CPUs even though the Backburner Monitor is only displaying 32.

Note: 40 is the numer of CPUs to use this will change depending the the machine. Also note that the command is only for mental ray renders.

If I try putting in either of the following in the "Additional Options" box, the render just doesn't start:

-rt <int>
Specify the number of rendering threads.

-art
Enable this option so that Maya automatically calculates the number of threads that should be used to best take advantage of the CPUs (or cores) on your workstation.

- from http://forums.cgsociety.org/archive/.../t-835741.html

Thanks for your time!