Resolve 9 Lite- Slow Render with Quadro 4000. OSX

[Juan Salvo]

Think your issue is RAM. Resolve 9 is now 64bit and the minimum recommended RAM is 12GB. It definitely benefits from even more than that. Preferably 24GB. Adding RAM in multiples of 12GB is beneficial as it allows the MacPro to function in a triple channel config. So best are 12. 24. 48.

This is covered in the Resolve config guide. Additionally the q4000 is a very weak card.

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[Margus Voll]

I will second to that.

4000 is really anemic for gpu. for primary gui card it is ok but for rendering gpu it is really weak.

—

Margus

https://iconstudios.eu

DaVinci 8.2.1 OSX 10.7.3
MacPro 5.1 2×2,93 24GB
GTX 470 / Quadro 4000
Multibridge 2 Pro

[Rohit Gupta]

I think you are just running into the limits of your Mac Pro 3,1, memory bandwidth and CPU speeds. Given the fact you see the same speeds whether you use only the GT120 or both the GT120 and Q4000 kind of confirms the same.

You should be able to confirm this by running the Activity Monitor and see how busy your CPUs are during the render.

[Grant Mcphee]

Hello All,

Thanks for all your help and suggestions.

I’m back home now where I’ve been able to try a few tests.

I’ve tried the Quadro in another Mac (4,1) and it is working fine and giving me around 50fps.

I’ve upgraded to 12GB and it does not seem to have made any difference at all.

I’ve tried different operating systems, re-installing drivers, trying a GTX285, swapping cards around, different GUI card.

It does not seem to make any difference, I can’t really get much more than 28fps, and an average of 23.

I can’t believe there would be that much of a difference between a 4,1 and a 3,1.

It feels like it’s not taking advantage of the GPU when rendering, although it seems to be using a bit of it.

Any help would be greatly appreciated.

The only thing I’ve not been able to try is having the same setup in a different 3,1 Mac Pro.

I’ve attached an activity monitor screnshot when rendering – 4541_render.jpg.zip

And When playing back – 4540_playback.jpg.zip

Thanks again

[Rohit Gupta]

Both the PR and DNxHD are CPU based codecs – so the Mac Pro 3,1 is definitely the bottleneck. With the latest Mac Pro, and faster CPUs, you should be able to get much faster render speeds, especially if you can use the 12-core ones.

[Grant Mcphee]

Thanks Rohit,

When using Resolve 8 I would get the same speed on my 4,1 and 3,1 (with Quadro4000).

When using Resolve 9 I get 50+ fps on the 4,1 with the Quadro and 25 without.

I get 25 with or without on the 3,1.

THe Quadro is definitely speeding up render times on the 4,1 but seems to have little to no effect on the 3,1.

There surely can’t be that much difference between the 3,1 and 4,1. I would maybe expect something like 35fps with the Quadro.

THey both have 12GB RAM.

Thanks again.

[Rohit Gupta]

What speed were you getting with V8.2 on Mac 3,1?

[Grant Mcphee]

I was getting 19.5 fps on the 4,1 and I was getting about 16.5/17 on the 3,1 so I was expecting that ratio to stay fairly similar, which it does without a GPU.

With the GPU added the 4,1 really takes advantage of the new optimising but the 3,1 just does not seem to, except for playback.

8.2 only ever really used the GPU for playback, as far as I’m aware.

Thanks

[Rohit Gupta]

All your figures confirm the bottleneck of your Mac Pro 3,1. Sorry, there’s not much we can do to speed it up further.

[Grant Mcphee]

Thanks Rohit.