Isadora performance and frame rate drops without user input on Mac
dbengali last edited by
I have come across an interesting situation (and a sort of workaround, at the end) that seems important to post -
Isadora 3.2.6 on Mac Pro 2013 ("trashcan") running latest Big Sur 11.7.2 or 11.7.1
Theater production where isadora cues are driven by MSC from lighting via the JumpToCue actor, so in the course of a normal performance, no user input occurs on the isadora computer during the duration of the 90 minute show. 30 fps target frame rate, content is images and 30fps videos. Probably about 75 scenes / cues in the show. Some scenes just play the content, some pass the content through few actors for color adjustment, and some scenes are empty with nothing in them.
We observed that after starting up isadora, things worked well, but after a while we would start to see increased stuttering in video playback throughout the show, including very simple scenes with simple video playback. This would occur if we sat in one scene with looping video, or progressed through the scenes of the show.
Looking at the FPS indicator, the FPS was dropping as well. Even in empty scenes with nothing at all in them, the fps was dropping to 28, 27, or 26 fps. If I moved the mouse or click on the screen, either inside of our outside of the isadora window, the fps suddenly would go back up to between 29.9 and 30
I started taking careful notes on this, and determined that after about 6 minutes without any user input, the performance and frame rate would drop. Wiggling the mouse would fix it, and then after approx 6 minutes the fps would drop again. This happened in all parts of the show, regardless of what kind of content was playing. Once the frame rate dropped, it would not recover on its own until i moved the mouse again, suggesting that the issue was not an intermittent background process that was starting up on system idle, as one would expect any process like that to eventually complete.
I verified that there were no user-accessible settings in power management that could be affecting performance. No settings to put disks to sleep, or save power. Spotlight indexing disabled. No adobe software on the computers. Same behavior observed on two separate computers (our main and backup) under the same show conditions.
The solution ended up to be installing a free tool called Jiggler This would wiggle the mouse and reset the system idle timer at a regular interval. With this tool running with an interval of 5 min, we now have clean shows without any FPS drop.
Maybe there is some other solution that someone knows. For us, this was the only method we found, and it hopefully may be helpful to others.
thank you for sharing your experience here. I would like to add my own here as well, which I actually observed quite often over the years, on different setups and combinations of hardware, OS, and Isadora Version and with very different Isadora patches.
At the Moment I'm using Isadora 3.2.5 on a Windows System for a theater production. Mainly live Camera input with 4 feeds (3 SDI inputs with BM Decklink duo, 1x USB HDMI Capture device) and some effects like color adjustment and chroma keying, as well as simple mapping (corner correction). This production is running on a aomewhat regular basis every some weeks, with the same setup.
What I observed is, that the same setup most times run smooth with stable FPS (mostly 25fps) and an exaptable Load. But now and then, both is dropping/rising and sometimes can't even be fixed by deactivating all scenes. This sometimes happens straight from the beginning, like just opend the project, sometimes only after quite some time. Restarting Isadora often (but not alway) helps. Like said, this is on always the same project / setup, but similar experienced quite often over the years on different setup/ projects.
As I could never find some real pattern, I did not report it yet.
Some other behavior I found, which is quit similar to yours, is a frame dropping/ Load rising, when having Isadora in the background (eg. while opening an explorer/finder window, etc.), which is recovering right after Isadora GUI coming back into focus.
I am raising this issue with the Technical team. If the OS is throttling Isadora in any way, we want to know about it and intend to correct the problem.
mark last edited by
Hi there, Mark here. We've discussed at our tech team meeting today and I personally have no answers as to why this would on macOS. We have added as a concern and will be investigating it over the coming few weeks. If we can find a way to recreate the problem on our on computers, I (meaning Mark) will put some code into an Isadora debug version to monitor this and see if we can prevent it.
dbengali last edited by
Currently remounting an older show and had the opportunity to verify that I see this same behavior way back on OS 10.14.6 Mojave and Isadora 3.0.7
This show mostly driven by OSC from another computer, so there are periods of time with no user input to the video computer. Isadora frame rate drops down to around 26 after a period with no mouse or keyboard input to the computer, and comes back up to 29.8 to 30.0 once the mouse is jiggled by a person or programmatically. Load is reported as low throughout; this is not a high-load show.
I found out the latest version of Jiggler is not compatible with Mojave so I downloaded and installed version 1.7 which works and solves the issue.
This show happens to also be on Mac Pro 2013 “trash can” as were the computers in my original post. I haven’t had a chance to see if the same thing happens on other hardware. But at least on the 2013 Mac Pro it has worked this way for a quite some time back into the past it seems
wondering if the technical team has been able to reproduce the behavior?
We weren't able to get any conclusive data last time around but we're doing another round of tests now.
I am now seeing this issue on my test machine. It appears to be very reproducible, therefore I expect we will be able to get to the root of it shortly.
We've discovered that a way to prevent this from happening is to go into Isadora Preferences and set Display Refresh to "Off". The drop happens at almost exactly five minutes no matter what media we are playing (and even if we're not playing any media at all!), so we believe it's not to do with our playback engine but instead is related to something sneaky Apple is doing behind the scenes to try to be efficient when a computer is seemingly "idle". We're going to investigate this further, but we wanted to let you know about the workaround we found during our testing.