Iris 2x model extremely slow on Apple Silicon after model update

[If you are posting a new bug, please include the following]

  1. The bug / behavior you have encountered
    Iris V1 and V2 are extremely slow on Applesilicon with the 2x model. Iris V1 was blazingly fast with the (where the release notes also stated a speed gain) but that was lost with encoding speed down back already in the 3.4.0 Beta.
    When Iris V2 was introduced it had good speed up to the -but with the following releases speed drastically reduced (about 60% of the former fps). Since this is now also the case when I reinstall the formerly fast I believe this is due to changes in the Iris model itself and not the app.

  2. Mac Studio M2 ultra 24c/60c, 64GB RAM, MacOS Sonoma 14.0

  3. Your log files (Help > Logging > Get Logs for Support)
    Since there’s no “error” I don’t think that log files will be helpful here

  4. Any screenshots as necessary
    The exact same task encoded with different versions:
    Iris V2 with the - 6 min 2 sec encoding time

Iris V2 with the 3.5.1 release - 9 min 54 sec encoding time

Iris V1 with the - 4 min 55 sec encoding time

So: where has the speed gain that was announced with 3.4 gone and why? Especially as there seems no really visible difference in the output before and after.
And 10 minutes instead of 5 minutes on the exact same machine with the exact same task definitely is a deal breaker for using newer versions.

P.S.: This seems to affect mainly the 2x model of Iris and you can see this speed anomaly also in the benchmark with the 2x model being merely faster than 4x.


Thanks for this detailed report. Our model development team is currently working on optimizing Iris v2 2X to run faster on macOS systems running Ventura or Sonoma. We hope to have an update out soon with these changes!


Just reapply those speed changes that you had from 3.3.x to for Iris V1 that seemingly somehow got lost later on (in the process of patching the Sonoma issues?) and also regain the speed of Iris V2 we had until the last model update.

(personally I do care more about the speed of Iris V1, but there are others that like V2 and from the earlier versions I do know that V2 can run nearly as fast as V1)

Anything new here?
On the M1 Pro Iris 2x sometimes is even slower than 4x.

And, there are new findings:
Iris V1 while being fast after the speed improvements in the model suddenly had major artifacts under MacOS Sonoma Beta.
A fix for this brought the speed down (and a later fix for visual glitches on certain configs even more so).

BUT: now the old (formerly buggy but fast) model seems to run under the latest Sonoma 14.2 without artifacts. So Apple seems to have fixed something?

Maybe you could try and revert to the older fast code?

Please please fix the speed.

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