I Don't *Think* My GPU is being used to Iray Render

Tinjaw

I have the option checked to use both CPU and GPU. However, when I use GPU-Z to monitor the usage of my GPU, it is between 6%-16%. I have a GTX980 w/ 4GB.

Any idea how I can confirm, and or fix, this?

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I may have spoken too soon. If I let the render run longer, the GPU seems to kick-in. Maybe the first part of the render uses CPU only, thenb GPUs kick-in for later functions.

mjc1016

Depending on the items and shaders used there is a lot that goes on before the render actually 'gets going'...and that may be what you are seeing. 

Khory

When mine cuts out it doesn't have any activity at all per GPU-Z. I am sure there would be minimal activity if my screen etc were not on a different (teeny built in) graphics card. Does it seem if the render is going slower than the norm? As in hours instead of minutes.

Tinjaw

Render times look good. I did an Iray render 2581x1451 and it took a little over an hour. The GPU kicked-in after it got to about 1%, I saw it on GPU-z.

nicstt

If you keep rendering similar, keep an image open; it will start rendering quicker, anything up to five or so minutes; only really worthwhile if almost no textures change (or shaders); just be aware it does take up a little memory of the card; it could be worthwhile rendering a small resoluton one and stopping it as soon is the render-image first appears.

It also seems to speed up spot renders too.

heinzerbrew_f94794efff

have you checked C:\Users\"you user name"\AppData\Roaming\DAZ 3D\Studio4\log.txt

it will log what is being used to render. i dont have a nvida card so i can't show you an example of when it drops to cpu.

bshugs@hotmail.com

Happens to me sometimes, though when it does, my CPU usage is maxed out (instead of 30-60% where it normally hovers).  If you look into your Log file you'll see something like this:

Iray INFO - module:category(IRAY:RENDER): 1.4 IRAY rend info : Falling back to CPU rendering.

Iray INFO - module:category(IRAY:RENDER): 1.0 IRAY rend info : Retry rendering with other devices.

Iray INFO - module:category(IRAY:RENDER): 1.0 IRAY rend info : CPU: using 4 cores for rendering

Iray INFO - module:category(IRAY:RENDER): 1.0 IRAY rend info : Rendering with 1 device(s):

Iray INFO - module:category(IRAY:RENDER): 1.0 IRAY rend info :     CPU

Iray INFO - module:category(IRAY:RENDER): 1.0 IRAY rend info : Rendering...

As, you can access the log from Help -> Troubleshootings -> View Log File...  I put a button on my toolbar for it.