Distributed rendering (CPU) in vray 5 not working efficiently (really slow)... disappointed

[LQ2]

Hi,

I've been using vray 3.7 for ages now, and have just updated to vray 5. I thought this would be a really great upgrade, but have been rather disappointed with the CPU distributed rendering.

The issue manifests itself the same way as it did when I first started with *vray 3* - looks like it was actually vray 2 (see post link below). There was a workaround solution provided back then, but annoyingly this doesn't seem to help this time

I send a render using CPU distributed rendering (using vray 5 sp2) to my 5 render nodes. Once they have registered the job and loaded the scene, I get a vast array of buckets arriving from the render nodes. All good till now. However, slowly the buckets from the nodes disappear, until they seem to have all gone, then they all reappear. This is REALY inefficient as it means that they seem to have to wait till the slowest core on the slowest machine has rendered before they each receive a new set of data for a new bucket to render. My local machine renders as expected as once a bucket has rendered, the a new bucket is allocated to that core and it carries on.

Previously, the solution was to set a render time script to set the number of active local cores to 1 core (2 virtual cores) lower than the total available locally. This freed up a core to do the distribution allocation. This worked very well. This (the same script) does not work anymore
This is a link to the previous post (any years ago) where I had more or less the same problem: https://forums.chaosgroup.com/forum/...ses-now-slower

I hope someone can help with this as again, it's a bit disappointing from a new version of v-ray to be going slower.

Cheers,

Bill

[LQ2]

I have to add a note to this, as things seem to have changed since my first sending of the render and my initial dissapointment.

I have changed the system environment variable for the number of cores that vray uses from 32 to 30 and restarted 3ds Max. I then tried sending a render using distributed rendering. This was again disappointing, so I cancelled the render part way through. It's worth noting at this point that I have only let one previous render finish as waiting for the entire render to complete seemed pointless. However, since changing the environment variable, I also changed the bucket size from 128 to 32. This appeared to make no difference, and the render nodes seemed not to work properly still, but I let the render complete. The render nodes seemed to do very little in the way of prepass or actual rendering. I then changed the bucket size again, back to 128 and started the render again. This time, however, all the render nodes kicked in and they rendered as I expected; each time a bucket completed it was reassigned and continued to render. This was then a VERY fast render.
I should also note that I have changed from primary engine "Irradiance map" to "Brute force". It would appear that vray 5 doesn't like the Irradiance map anymore. Could this be the problem? I have now switched back to the Irradiance map in the primary render engine and again the distribution is terrible!

This is very encouraging. I'll continue to experiment and see if I find any more out.

Would still like to hear any thoughts or explainations.

Bill

[nikoleta.garkova]

Hi LQ2

Thank you for the details provided. Just to update you here that your case is being reviewed and we'll let you know when there is any movement regarding the matter.