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Fusion 9 OpenCL slower?

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Fusion 9 OpenCL slower?

PostThu Aug 03, 2017 11:34 pm

Hi all,

Can anyone confirm they are seeing the same thing as me - openCL seems slower than CPU in Fusion 9?

Test - I took a DnxHR movie and connected it to a color corrector with an elliptical mask attached. So there was a circular color change in the middle of the frame.

With OpenCL OFF in the color corrector, playback was real time. With OpenCL on, playback dropped to 8FPS.

My system is 12 core CPU / 2 x NVidia Titan / Win 10 64bit / 64GB Ram / 600Mbytes-sec RAID.

Interestingly, GPU usage (as measured by GPU-Z) shows less than 4% usage with OpenCL on and around 6% usage with it off. Perhaps this is just due to more interface updates with the higher playback rate. I tried messing with the prefs>gpu settings, for example, specifically setting the target card, changing caching etc, but no difference.

Am I missing anything - any set up to enable the GPU?

Thanks :-)

Bryan Ray

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Re: Fusion 9 OpenCL slower?

PostFri Aug 04, 2017 6:32 am

I have noticed the same thing. I'm doing some more rigorous testing right now, comparing Fu8 to Fu9, with and without OpenCL enabled. So far, Fusion 9 with OCL is faster on a couple of tools, evenly matched on a few more, but noticeably slower on most. The system specs I have been testing with are similar to yours, but on Windows 7.

Max Seredkin

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  • Joined: Sat Jul 29, 2017 11:00 am

Re: Fusion 9 OpenCL slower?

PostFri Aug 04, 2017 8:05 am

The big scene in FUSION 9, including 3d and various processing threads, works with Opencl 30% slower than the same scene in FUSION 8

Vladimir LaFortune

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Re: Fusion 9 OpenCL slower?

PostFri Aug 04, 2017 8:24 am

It's going to be a long road

Tomek Sadowski

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  • Joined: Sat Dec 24, 2016 3:40 am

Re: Fusion 9 OpenCL slower?

PostFri Aug 04, 2017 5:34 pm

Much slower. With demo spaceship project 2 times slower than Fu8.
GPU load is small (GTX1070). Checked on different OpenCL settings. (playing around 1.4fps)
Resolve Studio 14b7 | Win10Pro 10.0.15063 | i7 2600K | GTX1070 (382.33) | 24GB RAM

Phil Hoppes

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  • Joined: Sun Aug 06, 2017 10:21 am

Re: Fusion 9 OpenCL slower?

PostSun Aug 06, 2017 10:32 am

I have found Fusion 9 to be at best only equal to Fusion 8 when rendering CPU only on Windows 10 and significantly slower when GPU rendering.

Below is a screenshot analysis that I did with a fairly sophisticated scene that renders one 4K frame (4096x2304) into a 16bit EXR file. I ran the render on my MacBook Pro and my Windows 10 workstation. The specs on both those machines are seen below the data. Note the Win10 workstation actually has 2xGTX1080 graphic cards NOT in SLI mode so they are specifically set up for GPU rendering. I rendered the scene with OpenCL setting at Auto, GPU, CPU for both Fusion 8 and Fusion 9 on both machines. Render times are in seconds.


This is a screenshot of the node network. You can see the details but it's not trivial.


Ryan Bloomer

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Re: Fusion 9 OpenCL slower?

PostSun Aug 06, 2017 1:14 pm

The delta keyer is also about 2x as fast with 10bit 4k dpx sequences when turning off the OpenCL option. I've tried on two different computers, and different locations from the loader (network and local) looks like it is the OpenCL what's causing the slow down.

Kel Philm

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Re: Fusion 9 OpenCL slower?

PostSun Aug 06, 2017 9:19 pm

I also ran a test with a heavy comp I have and found it ran around 7% slower in v 9.0 over v 8.2 on Win 10 with GTx 1080. Will try it with open CL switched of and see what happens.
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Re: Fusion 9 OpenCL slower?

PostMon Aug 07, 2017 2:10 am

One thing to check is your OpenCL caching pref. This defaulted to Off/disabled, which was fine for the few heavyweight OpenCL tools in Fusion 8 - but may actually slow down the many lighter tools in Fusion 9, because transferring images to and from GPU memory is relatively slow.

Full caching allows Fusion to pass GPU images from tool to tool without downloading back to system memory, so this is recommended for general OpenCL usage. Basic caching always downloads GPU images right after processing, but still passes it on to the next too, while turning caching off will minimise GPU memory usage at the cost of more transfer overhead.

Bryan Ray

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Re: Fusion 9 OpenCL slower?

PostMon Aug 07, 2017 4:44 am

Turning on caching does significantly improve many of the tools I've tested, but it's still slower than OCL off.

Hideki Inoue

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Re: Fusion 9 OpenCL slower?

PostSun Aug 13, 2017 5:31 am

New Delta keyer is great but extreme slow. I found OpenCL mode is slower than CPU. I made a simple comp that have 4K footage and just merge. It seemed to be slower than Fu7. I found OpenCL option in merge tool. :?

Win7 and Quadro K4200

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