Cool.

At least we know the 64 bit hardware will perform reasonably well.
1080p mkv performance seems to vary from file to file on a G5, but again 720p is consistently good.

As on the A1222, its fair to say that a T10XX cpu based solution might have had issues with higher resolutions as well (although it would have some edge).

And to be a complete trouble maker, even without UVD, even limited to a single thread, a Power 9 cpu ought to be able to handle 1080 mkv files.