High Frame Skipping Rate with Apple VT H264 Hardware Encoder

[Nathaniel_Wu]

I just switched from an Intel Mac to an Apple Silicon Mac (Mac mini, M2 Pro base model), and I was trying to record my screen with the Apple VT H264 Hardware Encoder, which is what I usually use on my old Intel Mac. It caused a whopping 89% frame skipping rate while the frame missing rate is 0%, and I haven't even tuned up the bitrate yet. This doesn't seem very normal.
I also tried other VideoToolbox hardware encoders, HEVC is slightly better, and only ProRes is problem-free. There's also no problem with x264 at high bitrates. So I'm just curious why the hardware-accelerated H264 encoder is actually running much slower, is this a known issue? Or did I do something wrong? I've attached some screenshots and the log.

 

[thomaslfessler]

What's your GPU utilization when recording?

 

[Nathaniel_Wu]

What's your GPU utilization when recording?

Overall between 60% ~ 80%, and OBS only uses about 20% ~ 30%, the rest is mostly used by the WindowServer process. And the WindowServer process only uses about 4% ~ 6% when OBS isn't opened.

 

[DRI374]

I'm sort of in the same boat here, did you manage to get this resolved?

 

[Nathaniel_Wu]

I'm sort of in the same boat here, did you manage to get this resolved?

I did not, I just used the CPU-only x264 encoder instead.