Playback fusion composition: poor performance

Hello,
I'm experiencing very frustrating poor performance during playback of my project. My project has 2 video tracks, but one of them, which is a fusion composition, is the bottleneck.
It consists of about 100 nodes, the media files are just pictures (no video). Basically I'm creating some graphics for educational purposes, so I'm really just displaying some images, text, or shapes and they animate with very simple effects, like moving masks and so on.
I'm using just the basic nodes: masks, text, background, transform and merge. No color correctors or delta keyers or any fancy node.

The problem is that the playback speed (frames per second) in incredibly low, even if I playback a section of the composition that has already been rendered, i.e. has a blue line above the tracks as opposed to red.

I have tried the following from the Edit page:
- select "Playback" -> "Use optimised media if available"
- select "Playback" -> "Use proxy media if available"
- select "Playback" -> "Timeline Proxy Mode" -> "Quarter resolution"
- select "Playback" -> "Render cache" -> "Smart" or "User"

I've also done the following in the Fusion page:

- Right click on the media out, select "Cache to disk"
- Right click on the player and select "Proxy" or "Auto Proxy"
- in the "Fusion" -> "Fusion Settings" panel, "Proxy" section: select "Update All" and set "Standard" to 30:1, tick "Auto" and set it to 30:1 too.

None of these result in a smooth playback.

My DaVinci Resolve version is 17.1.1 build 9 (free version).

These are the specs of my laptop
- CPU: Intel Xeon E-1545M v5 (4 cores, 8 threads)
- GPU: NVIDIA Quadro P4000 (8Gb RAM)
- RAM: 64 Gb
- disk: SK Hynix SC311 512GB
- OS: Windows 10 Enterprise, version 20H2

I think this hardware is more than enough for what I'm doing.

I know that the free version has some limitations regarding performance, indeed I see that during playback the CPU usage sets at about 40% and the GPU rarely goes above 20%.
What concerns me is that Resolve is actually using plenty (almost all) of memory, both RAM (~40 Gb) and GPU memory (~5 Gb), so it is definitely using these resources.

Is anybody experiencing the same? Is there anything else I can try?
Is creating a graph with about 100 (simple) nodes common?

Does the free version really perform that bad? Again, what is weird is that the GPU is doing something, and I have a pretty decent one.

Thanks for your help

Simone

[Peter Chamberlain]

If u render the fusion clip and place that back on the timeline does that improve performance?

Hi Peter,
thank you for your answer. If I render the fusion composition separately and import it in the project, the playback is indeed very smooth.
Unfortunately this is not a sustainable workaround. Just one 40 second Fusion Composition took 11 minutes to render and I want to make changes to it.

I have uploaded a screenshot of both the result and the graph of the fusion composition to give you more context.

There are two tracks:
- track 1 contains a footage of myself and in the Fusion page I add a Delta Keyer to replace the green screen with a white background. I also apply color grading in the Color page. The playback of this track is very smooth, once it has been cached.
- track 2 contains the problematic Fusion Composition. You can see that it just displays a few images and text and the graph contains about 100 nodes. Just a note: the nodes generate more that what you can see in that particular frame, for example the text and objects inside the blackboard change over time.

I thought that track 1, with the keyer and color grading, could have been a bit computation intensive, but actually the bottleneck is the other one.

If Fusion cannot handle about 100 "simple" nodes I will have to keep this in mind and simplify my graphs in future projects.

[Peter Chamberlain]

From ur report, the 100 nodes processing needs a much more powerful system to reduce the render time. Many vfx systems use render farms, in ur case simplify the comp or try on a much faster system. U could post the project archive and someone can try to give u a comparison ref.

A graph with mostly static elements and short range animations should cache itself like there is no tomorrow. To me it sounds like all the other posts where text effects are slow and caching in Fu page is broken. No-one uses render farm to render a powerpoint presentation equivalent of comp, this is just silly.

From ur report, the 100 nodes processing needs a much more powerful system to reduce the render time....

I think my system is already quite powerful (see the specs in my first post). Anyway, the composition that I posted also had huge rendering issues. The rendering either got stuck at some point, during the end of the composition, or the rendered output was incorrect, with one frame frozen until the end of the entire output video. I simplified the graph removing some nodes, and that fixed the rendering issue and improved the playback smoothness a bit.
To me, it looks like Resolve processes the composition quite inefficiently, with both CPU and GPU usage much below 50%.
I can try to put together a dummy composition just to stress the performance, so your developers can maybe have a look with a profiler.

A graph with mostly static elements and short range animations should cache itself like there is no tomorrow. To me it sounds like all the other posts where text effects are slow and caching in Fu page is broken. No-one uses render farm to render a powerpoint presentation equivalent of comp, this is just silly.

Are u saying I am misusing the tool? My composition is really similar to a Power Point one, but to me animating and compositing in the Fusion page looks just easier, and it should be fast.

Unless it's a 8k project your memory usage is a bit much, indeed.

Here are some suggestions

Can it be that some of pictures you use are way to big ?
Or that you try to render h265 or even h264 with the free version of Resolve. - don't !!


May be it helps to simply things

It seems that you probably need one picture, for the chalkboard)
the rest is a little square (in 2 different colours / three different places), 2 different small rectangles ( the keys) at in totaal 14 different places and maybe 4 text+ nodes .
-to highlight a key when pressed ( you could use a color transfer node // 14 in total )
-So probably 45-50 nodes.

Something similar renders quite fast, even in 4K.

What you also can do is try to renders parts of your composition to find out where your render problem is.

Hope it helps

Unless it's a 8k project your memory usage is a bit much, indeed.

Here are some suggestions

Can it be that some of pictures you use are way to big ?
Or that you try to render h265 or even h264 with the free version of Resolve. - don't !!

Hope it helps

Thanks for your suggestions. There are 2 pictures: the piano and the chalkboard. Both are .tif files of 8 Mb in size, 1920 x 1080, 96 dpi, 32 bit depth, uncompressed.
Simplifying the fusion comp helped, keeping the same (big?) images.For example creating the write on effect simply using the Write On option in the Text+ node, rather than having a bunch of moving masks.
But even if the images were way too big, the various "use proxy", "quarter resolution", "cache node to disk" options didn't improve at all.

I do render h264 with the free version. it is slow, but not super slow. To render an 11 min video it took an hour or so. I don't complain about this. The problem is the playback speed.

Thanks

1980 x 1080 isn't way to big, but 8 MB Tiff files are rather large. Especially for the small piano.

Try to use .png versions of files that you don't have to resize in Fusion (or only slightly).

It could solve parts of your memory / playback problems.

My system is a bit faster and I use the Studio version, but like I said a similar composition plays back 4k full speed. (a few jpgs, 40 nodes and stuff put on a 4k video file)

anyway success

No-one uses render farm to render a powerpoint presentation equivalent of comp, this is just silly.

Are u saying I am misusing the tool? My composition is really similar to a Power Point one, but to me animating and compositing in the Fusion page looks just easier, and it should be fast.

No, it was more a comment towards Peter, suggesting render farms are needed for rendering stuff like this. Tool is fine, just a bit broken.

Memory usage does not reflect the mem needs of single frame if any kind of cache is generated. All cached frames are put to ram if applicable, problem is rather that in some cases it seems Fusion does not read the cache as it should but reprocesses parts of comp that are already cached.

...problem is rather that in some cases it seems Fusion does not read the cache as it should but reprocesses parts of comp that are already cached.

I have noticed the same. Even if I see a blue bar which indicates the composition has been cached, the playback is super slow as if Resolve is reprocessing it every time. This looks like a bug.

Fusion integration is still buggy. As much as I enjoy Resolve 17 on the Mac, I'm always very careful to save often in Fusion.
It crashes a lot!