How to get 100% CPU in foreground render? (= starve a background render?)

[davexl23]

Hi guys,

got a tricky one:

I want my foreground render in VRAY to use 100% cpu. Having a 12 core machine with 24G ram means I will usually be running a background network render... but I want my foreground test renders ASAP = 100% CPU.

Right now the background network render still takes 50% CPU, even though it is set to idle priority. Likewise if I have folding@home running in the background, VRAY foreground will only take 50% CPU - despite priorities being idle on FAH, and Normal on MAX.

I have tried other programs, and they work as expected - eg Prime95 will 100% starve Folding@home etc

Any thoughts?

PS: Low thread priority in VRAY settings is NOT checked.

[jacksc02]

why dont you just pause the network render? seems simple to me

[davexl23]

why dont you just pause the network render? seems simple to me

Well, while working in the foreground I might do dozens of test renders per hour. Your brain might well be up to the task of pausing and REMEMBERING to unpause a background task a dozen times an hour, but I assure you, with a 2 year old daughter that can't sleep, my brain is not up to it. Not by a long way.

[Neilg]

Do you really need to do a dozen tests an hour? I think chris was assuming you do one every couple of hours so a pause is more managable.

[davexl23]

Do you really need to do a dozen tests an hour? I think chris was assuming you do one every couple of hours so a pause is more managable.

Guys, we are getting sidetracked here. The issue is that this new machine (12 cores/24 threads) is about 50% of my renderfarm, so I will be running things in the background. Vray, Fusion, Premiere, etc etc. But if I want to the foreground process to use 100% briefly for whatever reason, without killing the background, I want to be able to do that.

This is what priorities were invented for, and my question is why is Vray not working as expected behavior, and how do I make it?

[Donald2B]

You could try to make sure you send the renders to backburner using low thread priority in the VRay Miscellaneous tab.

No matter what you do, you are NEVER going to get 100% when trying to render if other things are being done on your machine. I have used multiple cpu machines for a LONG time and have setup priorities, but at the end of the day, I still will not get the performance I want. This is not a VRay problem since I Mental Ray and Brazil do the same for me too. It's just the way it is.

So if your test renders are THAT important, I would suggest pausing background jobs temporarily, or rethinking how much you actually need to test render.

[SimonC]

We have the following in a maxscript file in our maxscript\startup folder. It goes some of the way to solving this issue as all max server sessions (either DR or backburner) automatically are assigned to low priority.

if isNetServer() do sysInfo.MAXPriority = #low

HTH
Simon

[jordanw]

also, make sure that "low thread priority" is not checked in the render/system rollout