Compressor encoding time

Hello all!

Compressor 4.7 on a M2 Max Mac Studio, Sonoma 14.7.

I'm converting a 14 minutes 3840 X 2160 422 Pro-res video file to HEVC 8 bits, at 50 mbps. If I leave the default setting at the "Faster" single pass setting, it takes 4 minutes to encode, which seems to be very reasonnable. If I select the "Better quality" multipass setting, the time jumps to 2 hours and 22 minutes, which seems to be way too much!

In comparison, when doing H264 encoding, the change from single pass to multipass barely double the encoding time. We're now talking 35 times slower here!

Is it a question of the hardware encoder not being used if I'm outside of the default parameters? Or something else?

I can't readily distinguish between the 2 files, but this video is mostly steady talking head style, unchallenging material.

Thanks!