2 Max, 2 GPU, 2 Fast, 2 Furious!

[Sylk]

Hi there,

I'm curious so I did some tests... with rather interesting results about Animation Rendering


Why this? Because...

... During rendering the GPU does not work @100% continuously.

For example, when switching to the next image.
The code not only seeks the GPU; it also uses the CPU, it reads and writes data on disk and in memory, needs time to execute commands, etc.
And during that time the GPUs are not used!

I thought about how to fill those blanks to optimize the use of GPU and so I thought to make two images simultaneously. When GPU not used for the first image, it will be for the second one! And vice-versa.
The secret: 2 Max instances!


Now, here are my tests and their results.


The Context:

• - target: rendering 20 frames from non-static animation (particleFlow: fallin bolt nuts)
• - resolution: 1920*1080
• - render passes: 100
• - light samples: 3
• - max depth: 16
• - Depth of field: Off
• - Glare: Off
• - Tone mapping: On
• - vignetting: 5.0
• - image blur: 1.0

TEST 1: All-in-one

3dsMax Instances: 1

GPUs: 2
Frames: 20 (0 to 19)

Results:

Rendering Time: 11min 32s

GPU #1 usage: 93%
GPU #1 vram usage: ~900
GPU #2 usage: 94%
GPU #2 vram usage: ~700

TEST 2: Split animation. Open same scene on a second Max instance and just change frames range (e.g. First half and Second half).

3dsMax Instances: 2

GPU on Max#1: GPU#1
Frames on Max#1: 10 (0 to 9)

GPU on Max#2: GPU#2
Frames on Max#2: 10 (10 to 19)

> Both rendering started simultaneoustly

Results:

Rendering Time Max#1: 9min 58s
GPU #1 usage: 94%
GPU #1 vram usage: ~1100

Rendering Time Max#2: 10min 19s
GPU #2 usage: 95%
GPU #2 vram usage: ~900

TEST 3: Same as Test 2, but with both GPUs on both instances.

3dsMax Instances: 2

GPU on Max#1: Both
Frames on Max#1: 10 (0 to 9)

GPU on Max#2: Both
Frames on Max#2: 10 (10 to 19)

> Both rendering started simultaneoustly

Results:

Rendering Time Max#1: 9min 45s
Rendering Time Max#2: 9min 49s

GPU #1 usage: 98%
GPU #1 vram usage: ~1200
GPU #2 usage: 99%
GPU #2 vram usage: ~1000

Conclusions:

Time to complete animation rendering:

TEST 3: 9min49s. Both GPUs on 2 instances is better for lite scenes. Better optimization for GPU usage; more fast but more vram usage too.
TEST 2: 10min19s. Separate GPU for each instances produced no real optimization for GPU usage but is a good compromise between rendering speed and vram usage.
TEST 1: 11min32s. Both GPUs on 1 instance stay the better option for High poly scene which needs more vram. "Low" GPU usage; more "slow" but more free vram.



Thanks for reading. May this help You.


...
NEXT TESTS: Static animation

[Syrom]

Hmm... what did you gain from this? The render times are mere seconds apart.

[Sylk]

Hmm... gain of 1min43s for 20 frames, then how many for thousands?

[kahein]

so for 2000f (1mn20s) of animation, you gain approximatively 4h !
it's huge.
It would be great to know why ?

[Sylk]

It would be great to know why ?

I explained why:

Why this? Because...

... During rendering the GPU does not work @100% continuously.

For example, when switching to the next image.
The code not only seeks the GPU; it also uses the CPU, it reads and writes data on disk and in memory, needs time to execute commands, etc.
And during that time the GPUs are not used!

I thought about how to fill those blanks to optimize the use of GPU and so I thought to make two images simultaneously. When GPU not used for the first image, it will be for the second one! And vice-versa.

Clearly, with test 3 set, both GPU are used to 99-100% for 100% of time.