Vray 7 - Backburner - Extreme Performance Issues

[RedStar]

Figured I would make a new thread not to confuse it with the old one. But the old issue is back again. Link below is to the old topic which shows this was a Vray issue and the team resolved it once, would love a fix for it again.
Thanks!!

https://forums.chaos.com/forum/v-ray...ormance-issues

[hermit.crab]

Moving the conversation here. The issue discussed in the linked thread (internal bug-tracker id: VMAX-12423) seems fixed. I just tested this with the latest official V-Ray build and 3ds Max 2025, sending a Backburner job to my own workstation and I do not notice any freezing.

On a side note, what CPU do you use? There are some performance issues concerning certain models, which are visible even with Standalone (you may test this).

[Joelaff]

Can you elaborate on “certain models?”

[hermit.crab]

Can you elaborate on “certain models?”

Xeons and newer AMD processors. I've mentioned this by memory, but it may be already fixed.

RedStar Talked to Yavor about this and he told me they implemented a new environment variablem that controls the priority of network jobs through render managers. Go to the Windows' environment variable options, add this variable and check if the performance gets better:

VRAY_NET_RENDER_NORMAL_PRIO = 0

[RedStar]

Hi Hermit. My main workstation is a AMD 3995WX. My render nodes are mostly AMD 7950x. I am now having this issue on all systems. My main system is 128gm ram. Same job rendered perfectly fine with latest Vray6, now on Vray 7 hotfix 1 its impossible to do anything as soon as the server starts, but when I render locally zero issues. Was this fix added into a night build or offical release? I have 15 render nodes so updating them takes time and I usually try to focus on offical releases and cant be doing daily Vray updates while also having to do a lot of client work. Hope that makes sense. I will test this Variable thing today after a client call.

Also using 3d max 2024 on my end. I really hope that isnt an issue becase as I mentioned the same exact job allowed my computer to work just fine during render times but now on Vray 7.1 huge huge lag and hard to even close down the server.

Thanks,

[RedStar]

Hello Hermit,
I went ahead and made a video to showcase the issue is real and a serious problem on my end.

https://www.youtube.com/watch?v=r3IrxORfszM

[hermit.crab]

Was this fix added into a night build or offical release?

It was a nightly build (check the old thread), ̶s̶i̶n̶c̶e̶ ̶t̶h̶e̶ ̶f̶i̶x̶ ̶w̶a̶s̶ ̶a̶ ̶b̶i̶t̶ ̶o̶f̶ ̶a̶ ̶"̶b̶r̶u̶t̶e̶ ̶f̶o̶r̶c̶e̶"̶.̶

EDIT: The fx is in V-Ray 7, too.

I will test this Variable thing today after a client call.

Did you test it?

[RedStar]

It was a nightly build (check the old thread), ̶s̶i̶n̶c̶e̶ ̶t̶h̶e̶ ̶f̶i̶x̶ ̶w̶a̶s̶ ̶a̶ ̶b̶i̶t̶ ̶o̶f̶ ̶a̶ ̶"̶b̶r̶u̶t̶e̶ ̶f̶o̶r̶c̶e̶"̶.̶

EDIT: The fx is in V-Ray 7, too.



Did you test it?

I have not yet. I am curious what does this variable do? Does it start to limit the CPUs performance with Vray? I am not too educated on these things but if thats the case it doesn't quite sound like a proper fix to me if I am now not going to be using 100% of my CPUs power.
I was hoping Vray can fix the issue since it was fine before the update and as you see from my video I have proof that it works fantastic locally and complete trash through backburner.

[RedStar]

It was a nightly build (check the old thread), ̶s̶i̶n̶c̶e̶ ̶t̶h̶e̶ ̶f̶i̶x̶ ̶w̶a̶s̶ ̶a̶ ̶b̶i̶t̶ ̶o̶f̶ ̶a̶ ̶"̶b̶r̶u̶t̶e̶ ̶f̶o̶r̶c̶e̶"̶.̶

EDIT: The fx is in V-Ray 7, too.



Did you test it?

Hello again Hermit,
So for the sake of eliminating factors I went ahead and did two things.

Got the night build from 24-12-13 - This did not fix the issue and still runs awful
Added the Env Variable as you mentioned - This did not fix the issue and still runs awful.

So as of right now, Vray 7 still have the Backburner problem and there is no solution. While the rendering is still possible and does work, I would love to be able to actually use my computer if I need to. Please please have your team look into this because it was resolved in the past so I imagine they can do it again.

[hermit.crab]

I just tested this on our 88-core Xeon PC. Tested with 3ds Max 2024, latest official V-Ray, and again with the latest nightly build. Indeed, there is a huge performance loss (barely managed to stop the job). However, when setting up the environment variable and restarting the PC (this is important), everything worked out nicely and the PC was responsive as usual. Did you restart your PC after setting up the variable?

I am curious what does this variable do? Does it start to limit the CPUs performance with Vray?

Sets the thread priority to Low, so that other processes could run smoothly. This happens by default in local rendering via the currently hidden "system_lowthreadpriority" parameter.

I am not too educated on these things but if thats the case it doesn't quite sound like a proper fix to me if I am now not going to be using 100% of my CPUs power.

Using 100% of your CPU means not using it for anything else, leading to the issue you're reporting.

[RedStar]

Hi Hermit. I actually did not restart the pc!!
Question, will doing this limit the performance of the pc when it comes to render times? As you imagine, when doing animations render times are key, so due to my lack of knoledge, will low thread priority slow down rendertimes significantly?

Will try the variable again and restart pc! Thanks Hermit.

[RedStar]

Hi Hermit. I went ahead and added the env variable again. Rebooted my machine. Started a render, and still pure trash. Maybe I am doing something wrong but here is where I added it, and link below to a video showing the fantastic performance I am currently getting....

https://youtube.com/shorts/Sevpl35Xv...aQVzh7I_6Wn8ZS

[Joelaff]

Put VRAY_NET_RENDER_NORMAL_PRIO under variable and 0 under value. No equals sign

Right now you have Vray under variable. Then reboot or logout and log back in.

[RedStar]

Put VRAY_NET_RENDER_NORMAL_PRIO under variable and 0 under value. No equals sign

Right now you have Vray under variable. Then reboot or logout and log back in.

YOU ROCK!!!!
Okay, so Hermit this variable thing 100% worked for me to. I was thinking it was operator error so it def worked now that Joelaff explained how to put it in.

Thanks so much everyone!

[Joelaff]

I am curious what version added that variable ?