Poor performance with dual Xeon E5 2699 v3 (72 thread total) CPU's

[brobins]

Hi there,

We have noticed a specific issue relating to our new workstations that carry dual Xeon E5 2699 v3 CPU's & 128GB Ram.

The issue relates to poor rendering performance when compared to our old workstations dual Xeon X5680 (24 thread total).

A direct comparison on the farm, shows the new workstations finish a frame in 10:07s and the old workstation in 02:10s.

The scene is extremely basic. 1x Dome Light & 1x Vray Proxy Object.

Its probably worth mentioning that this only seems to happen when Vray Proxy Objects are using or if VRay Displacement is being used. Most of the time the new workstations are many many times faster on the farm than the old ones.

Does anyone have any idea why these new CPU's do not seem to get on with Vray Proxys or Displacement?

Many Thanks,

Ben

[vlado]

For displacement, make sure the "static geometry" option is enabled (it is ON by default for newer builds) in the VRayDisplacementMod modifier.

For the proxies, are they stored locally on the computer or fetched through the network? What is your dynamic memory limit set to? Does it make any difference if Embree is on or off?

Best regards,
Vlado

[brobins]

Regarding the proxies, they are usually stored on a fast network array, but for the purpose of this test scene I have the proxy object stored on the test machines local C: drive and the results are consistent.

Embree doesn't make any difference and the Dynamic memory limit is set to 0.

As soon as the frame buffer opens and the buckets pop up (on the 72 thread machine) it just seems to hang and go very slow. On the 24 thread machine the buckets begins rendering without any pause at all.

Its really quite perplexing.

Thanks,

[vlado]

Ok. Which V-Ray version by the way? We made some improvements for many-core machines for V-Ray 3.5. Still, would it be possible to get me that scene for testing to vlado@chaosgroup.com ? We have an 88 core machine here and I would like to profile the scene and see if there's something that we have missed.

Best regards,
Vlado

[brobins]

We're on 3.40 and it has been working well, but these issues with proxies and displacement have been reoccurring.

I will package up the scene + proxy now and send over.

Many Thanks

[brobins]

Email sent with test scene attached.

Many Thanks,

[brobins]

Just wanted to follow this up.

I uninstalled and reinstalled Vray and the issue has been resolved. Do you have any idea why something like this could happen and why a reinstall would fix the issues mentioned relating to Proxy objects and Displacement specifically?

Thanks,

Ben

[vlado]

Did you install the exact same version as before?

Best regards,
Vlado

[brobins]

Yeah, exactly the same.

Thanks,

Ben