Blackmagic Forum

Yesterday I installed V.17 Beta 6 and went along to create a fairly complex edit.

The steps I utilized were:

Loaded the material as Prores MOV files
Created Optimized Media on all (on SSD)
Laid down the edit
Added a few Fusion effects
Set the caching to "Smart" and activated all the caching options on the clips
So far so good

Then I placed an Adjustment Clip over two video tracks. The mere presence of the Clip itself dropped the performance to a mere standstill. It only had a color correction on it. I proceeded with masking. The speed went near negative.

I waited for caching and tried for a playback. For the first 5 seconds, it only showed 2-3 frames before the play became smooth. The audio started somewhat choppy (on a scale 1 to 10, a 4). The audio took a couple more seconds to smooth out.

Eventually, I tried adding a simple glow OFX. Then all hell broke loose. Cache became nearly non-responsive. Clips that has both Fusion (i.e. Glitch) and OFX glow rendered as fast as loading a BluRay movie from floppy disk. I'm exaggerating of course, but a frame took approximately 15 seconds.

Here is where it gets "interesting."

Cache stopped building altogether. I left my computer alone for about half an hour (for a 90sec edit) and came back to finally see the Timeline cached only under the User selection (Smart selection got rid of everything and never initiated any caching).

I played back the 90sec edit. The sound started a bit choppy (no difference from before), but the entire sequence only showed me approximately 7-8 frames. That was it. No playback at all.

Then I selected a few clips in the timeline and purged the OFX glow. Nothing changed. The non-existent performance endured as if I had them loaded with a dozen plugins. I lowered the wait time for the caching to begin down to 1 sec. When I attempted to cache, nothing would begin for at least 5 minutes.

Self "detonated" cache
After having the entire timeline cached, I went to a small portion of the work area to add one extra clip. Immediately, the entire cache (of multiple clips) went red. Mind you, there is no clip that goes from beginning to end in the edit to justify such an erroneous cache implosion. When the red came up, caching went to a full stop altogether. An attempt at playback would begin a partial cache at the play-starting position but would not continue caching at all, no matter the wait.


System of Test
OS: Windows 10 Home Edition
RAM: 32GB
GFX: NVidia RTX 2080 8GB
Drives (work): Samsung EVO SSD 1TB (cache) & 512 GB (clips & project)
Screen Resolution: Ultra HD 32"
Project Specs: 1080p @ 23.976 fps
Min/Max Active Clip Tracks at a time: 3 min / 9 max (same cache/playback issue in both occasions)

P.S. Creating and engaging proxy files and playback (at 50% resolution) rendered Resolved non-responsive for about 3-4 minutes. Playback ensued at much worse performance than non-proxy. Only 2 frames appeared out of the 90sec edit.

P.S.2. At the moment, the edit is basically unworkable. There are instances of a severe memory leak, shooting from 7.5GB to 29GB in a matter of seconds (between 9-12sec), even with Fusion Memory Caching off. In other instances, Resolve remains in memory even after I quit, maintaining a 24-25GB memory consumption.

You're not the only one experiencing these peculiar behaviors. I've had the same thing happen, in ways that you've described clearly, and in other ways that I don't even think I am able to describe due to the complexity or inconsistency of the problems' occurring.

I can try to explain one general example of my experience. Some days, some times, I will get to work editing a timeline and/or color grading or doing any number of the things that we do with Resolve, and the everything is moving like molasses, then after some time, and for some unknown reason, it seems that everything becomes super responsive, smooth and predictable, like a clog being cleared from a drain, everything just washes through. Other times, I might start off everything going smoothly, and at some point, whether I enable render cache or activate Fusion to get it's dirty fingers on my timeline, things will just slow down, either globally or only on a particular clip that for example is associated with Fusion, even when there is nothing going on as far as Fusion nodes are concerned (i.e. only MediaIn to MediaOut connection, nothing else in the pipeline.)

I wonder if MacOs is running background tasks, but a look at Activity Monitor reveals nothing is consuming any considerable resources. Just strange things, probably as you mention, memory leaks or system caching or some other software (code) routine/path that isn't working as it should, and corrupting the operation of things that normally do.