pc absolutely unusable when rendering

[super gnu]

windows 10, max 2021, latest vray, 3990x threadripper and 128gb ram. render is using about 90gb. i have changed 3dsmax thread priority to "low" but it does not help. (although it does allow me to type a little. )

im typing this and the letters are appearing a good 10 -15 seconds after i hit the keys. if i click on a window, it takes about the same amount of time to select. the mouse is moving jerkily, and i can forget actually manipulating the vfb. if i try to zoom in or out on vfb it literally takes 4-5 minutes to respond. the buckets in the render update their position every few minutes, jumping to a new position on the render ( its been rendering away, just not updating the interface. ) this seems to be more of an issue on some jobs than others. my current job is particularly bad. id love to set the affinity of max/vray to leave a couple of cores free, see if that helps, but i get "access denied" on the affinity settings in the task manager, despite being admin.. ive searched online and find no solutions.

in the past i have happily worked in one instance of max while rendering in another. this is obviously absolutely impossible now.

what gives?

[Joelaff]

Minimizing the other Max instances helps a lot in most cases.

[super gnu]

i dont have any other max instances open in this case..

[Joelaff]

Oh, sorry. I misread. Try updating the AMD drivers for the threadripper. That seemed to help quite a bit on my 5xxx series Threadripper. Knock on wood the 7995wx has not shown this behavior, though multiple instances of non-minimized Max do seem to be able to make it feel a hint more sluggish. It’s Win11 though, which could be different. (And has its own issues like file copy speed on high core processors)

Does restarting help? Always seemed to help for a while.

[Joelaff]

I assume you know about the Forest Pack bug that was making things far worse. If you have it installed, make sure you are in the latest version. Just having it installed could slow things down.

[Vizioen]

I assume you know about the Forest Pack bug that was making things far worse. If you have it installed, make sure you are in the latest version. Just having it installed could slow things down.

That was only during saving with multiple instances open.

I have a similar build (3990x) but with 256GB - windows 11 - Max 2023. Before it was windows 10 and 128GB but didn't have those issues.

I read some threads that outdated GPU drivers can also cause this, can't harm to update them.

What OP can do though is limit the number of threads used for rendering, as when you're rendering you're using all your cores. If you want to continue working while rendering, the cores that you use for other work will not be efficient, neither for rendering, so in the end might even be slower.

So if you want to render and work, set the environment variable VRAY_NUM_THREADS to a couple of cores less than your total amount. Environment Variables - V-Ray for 3ds Max - Global Site (chaos.com)

[Joelaff]

Was the Forest slowdown ONLY during save? I thought it slowed it all down because it pinned the Max GUI thread to proc 0 or something. Either way, make sure it is up to date.

I didn't find limiting the threads had any positive effect here. All the machines we had problems with are on Windows 10, but all our machines except the 7995WX are on Windows 10.