Can we get the "Low CPU Priority" option back?

[gardocki]

We've got a small render farm, but a few of our workstations also double as render nodes. We used to be able to add them to the farm when we're doing light tasks like word processing or web browsing, but now with Vray 4, they always default to high cpu priority when attached to the farm and makes them unusable while rendering. Is there a way to change this behavior? (scripting, etc?)

[^Lele^]

The option is now always on, i believe.

[alex.nozadze]

according the vraylog - yes, low thread priority is always on .....

[^Lele^]

Should you wish for the Max task (as opposed to V-Ray's thread only) to stay at lower priority, use an external tool (like this article suggests) to set it permanently.

[gardocki]

As I understand it the default is always on for local renders, off for batch renders. But if it's always on then there's definitely a performance difference compared to Vray 3.

[^Lele^]

As I understand it the default is always on for local renders, off for batch renders. But if it's always on then there's definitely a performance difference compared to Vray 3.

Yes, indeed.
.system_lowThreadPriority exists, of course, but it's not doing anything at all anymore.
You're better off using one of the the free utilities i linked above.
I have had this low-process-priority setup going for ages (until roughly a year and a bit ago. so take with a pinch of salt), without any particular issue in working with Max, btw.

[william.morris]

There is certainly a difference in lag since the option has been removed, even though its the option is supposed to be permanently on. All out machines in the office lock up when rendering, this never ever happened when we used vray 3.0.

[gardocki]

Thanks Lele. Prio seems like it'll be a decent solution but it's annoying to have to find a 3rd party workaround for functionality that used to be standard.

[^Lele^]

I suppose it could be made to stay low-prio for slaves as well, but i wouldn't know if there'd be an important performance penalty with it (unlikely, in this day and age, but i really am not knowledgeable nearly enough to state anything for sure.).

[vlado]

The option is always on if you render in a 3ds Max GUI session, that's why it was removed. And it has always been off for render slaves since forever, there has been no change in that regard.

Best regards,
Vlado

[LeePuznowski]

The option is always on if you render in a 3ds Max GUI session, that's why it was removed. And it has always been off for render slaves since forever, there has been no change in that regard.

Best regards,
Vlado

Right, but it is actually doing anything? Using IPR completely throttles my CPU thus making any iterative lookdev impossible. This using the current Vray Next 2.1.

[yavor.rubenov]

In one of your problem scenes can you check the current value of the option with the following MAXScript:

renderers.current.system_lowThreadPriority

The default for new scenes should be 2 but if it is not so in your scene - you can explicitly set it to 2 with this MAXScript:

renderers.current.system_lowThreadPriority=2

Also can you check the value of

renderers.current.system_numThreads

its default value should be 0. When zero V-Ray will use all threads for regular rendering and all threads -1 for IPR.