Question about render subD and memory usage

i53570k

I have a scene with just one G8F character and the render subD says <?>.  If I move the dial by one it changes to 3 so I assume the <?> means 2. 

At <?> the log says geometry usage of 63 MiB and texture memory usage of 1.14 GiB.  I have a 4 GB GTX980 (I asssume Daz3D GiB means gigabyte).  Iray renders in GPU with all 4GB VRAM used and is super fast finishes at 3 min exact.

If I dial the render subD by 1 to 3, the log says geometry memory usage of 669 MiB and drops to CPU due to out of VRAM.  There is no record of texture memory usage.

I know subD goes by a factor of 4 but in this case geometry memory suage went up by 10x and I still don't know what total requirement is at subD3.

 

 

Also, regardless of GPU or CPU render I keep getteing this warning:

WARNING: ..\..\..\..\..\src\pluginsource\DzIrayRender\dzneuraymgr.cpp(305): Iray [WARNING] - IRAY:RENDER ::   1.0   IRAY   rend warn : The 'iray_optix_prime' scene option is no longer supported.

But I have optix prme acceleration unchecked.

DrunkMonkeyProductions

First parts easy.

a '?' in any slider means that multiple sliders, with the same name,  are selected and different numbers are being used in each.

In this case, either a 'follower', such as hair or clothes, or a 'sub item' such as two morph dials sharing a 'name'.

You can turn this off by either right clicking on the tab, or selecting the tabs menu button, and clicking on one or both.

attached a couple pic to help.

The actual numbers can be anything, when you ticked the + it just reset all the values to 3 to match. It usually adjusts the value to the highest value of one of the dials, but don't quote me on that.

 

sub d can be a bit hard to understand at first.

Each increase is a 4x increase, over the previous level. 0 to 1, 4x, 0 to 2, 16x, 0 to 3, 32x, 0 to 4, 64x.

For instance, sub-d 0 for g8f is 16368(per scene info), at sub-d 3, the total is 1047552, an increase of 32x.

 

I was actually doing some bench marking this week testing this exact thing out.

My ram usage at Sub-d 0, 4085MiB, sub-d 1 4461MB, sub-d 2, either 4664, 5443 or 6019.

It would stabilze to the 6019 after the 4th or 5th test render.

And the sub 5GB was on a totally different card than the 5443 and 6019.

Made benchmarking fun with the various number.

i think sub-d and iray have a bit of an issue in 4.12

 

the error,

latest build of DS doesn't support optix, so it's irrelevant whether the box is checked or not, and apparently it's just throwing a log error, shouldn't be impacting render times.

Another 'error' to ignore.

EDIT:I'm too tired to be doing higher math.

i53570k

Thank you for the explanations.  Clicking the items one by one is quiet revealing.  It turns out a geoshell at subD 3 killed the whole GPU rendering.  Everything else was either 1 or 2.  For some reason that shell alone raised memory calculation for the whole scene by a factor of almost 10.

I guess Iray @ 4GB GPU is now obsolete if one wants even a tiny bit of subD 3 in a scene.  Even 8GB GPU will probbly drop to CPU with more than 2 characters if there is subD 3 element.  No point spending money on HD characters.

 

DrunkMonkeyProductions

Just to clairfy, that scene i was testing was 34 g8f's at render sub-d 2.

Crop top, thong, stockings, hair, glasses. hdri lighting.

What's causing the biggest ram issue with older cards, 10xx and below,  is the changes to Iray.

For older cards, it's an absolute memory hog, but it can be insanely faster than 4.10

that same scene was only 2769MB in 4.10 at sub-d 2.

But it took over an hour in 4.10, as opposed to 20min in 4.12 on the same gpu.

 

codex34_f5f1fb6f55

Thinking your maths is off, x4 for each level @subd2=x16 @subd3=x64...  @subd2=261,888 quads  @subd3=1,047,552 quads

I actually have a question, what's the memory usage if you set the view subd to 0 and render subd to 3, as apposed to having them both at 3?

TheKD

Viewport subd at 2 = Geometry memory consumption: 15.162 MiB

Viewport subd at 0 = Geometry memory consumption: 15.162 MiB

 

Doesn't seem to affect it, or it's so little that 3 decimal places are not enough to show it lol

DrunkMonkeyProductions

codex34_f5f1fb6f55 said:

Thinking your maths is off, x4 for each level @subd2=x16 @subd3=x64...  @subd2=261,888 quads  @subd3=1,047,552 quads

I actually have a question, what's the memory usage if you set the view subd to 0 and render subd to 3, as apposed to having them both at 3?

good catch.

had it right in my notes and whiffed it in the transfer.

codex34_f5f1fb6f55

Did a quick test with a subd cube, viewport and render subd@7 (max in my viewport settings), you do get increased memory usage.

With the viewport at 0 the render subd uses 1gb system mem for every 1mil quads, not got a GPU so can't do the test for system v's GPU usage.

30 minute wait for system to stop sulking for a cube at subd 11, 25mil quads is about 25gb, I got 8gb.

Found the biggest memory usage is having more than one render window open, so when you don't close the previous render the memory isn't freed up.

Mediasylum

One of the biggest memory consuming things is the iRay itself.

Windows10 idle VRAM - 200Mb

Daz Studio running, empty scene - 295Mb

Launching iRay render (128x128 px) with default settings (open render window) - 2211Mb

Closed render window - 2185Mb

Launching iRay render (2048x2048 px) with default settings (open render window) - 2308Mb

Launching iRay render (4096x4096 px) with default settings (open render window) - 2883Mb

Swithching iRay to "Scene only" lights (with one polygon plane and a spotlight in a scene) doesn't change memory consumption significantly.

So it allocates 1.9Gb of video memory after first rendering and doesn't release it until the Studio is running.

Thus 4Gb videocards are left with just ~2Gb of VRAM for actual scene data :(

Richard Haseltine

codex34_f5f1fb6f55 said:

Did a quick test with a subd cube, viewport and render subd@7 (max in my viewport settings), you do get increased memory usage.

With the viewport at 0 the render subd uses 1gb system mem for every 1mil quads, not got a GPU so can't do the test for system v's GPU usage.

30 minute wait for system to stop sulking for a cube at subd 11, 25mil quads is about 25gb, I got 8gb.

Found the biggest memory usage is having more than one render window open, so when you don't close the previous render the memory isn't freed up.

That does depend on the card to a degree - for non-RTX cards Iray will load additional code into the GPU to handle the features that RTX handles when present.