Outstanding. I found that doing 4K HDR10 tonemaps to 1080p barely loaded a Mac Studio M1 Ultra 128 GB with NVME and PGS subs. Screenshots are below.
| # At Once | Source | Target | # of Subs | CPU | RAM | Power[1] | Fan RPM |
|---|---|---|---|---|---|---|---|
| 16 | 4K HDR10 HEVC | 720p SDR x264 | 5 PGS | 23% | 44 GB | 36 VA | idle |
| 32 | 4K HDR10 HEVC | 720p SDR x264 | 5 PGS | 28% | 58 GB | 40 VA | 50% |
| 32 | 4K HDR10 HEVC | 1080p SDR x264 | 22 PGS | 20% | 56 GB | – | low |
@Volts you seen this? I could do maybe 32 before Apple tells me
Warning: Kernel Task has crushed you.
EDIT: while I managed 32 transcodes today, it wasn’t the smoothest test when one iMac had a Plex Player crash as i was about to do the screenshots.
EDIT2: I found the maximum was 32 transcodes. Any more will not use HW. Tested only 1080p. Increased to 22 PGS subs. No VA reading because the laptop was plugged in. The source bitrates avg. 25 Mbps. The previous crash I had testing 720p was due to the Mac Studio DoVi screensaver coming on.
Volt Amps for an inductive load displayed on a Cyber Power UPS where 36 VA ~= 32 W AC but the conversion really depends on what’s plugged into the UPS. ↩︎
