Proxmox LXC + firestick client

[TheDreadPirate]

ffmpeg will always transcode as fast as possible. So the fact that the GPU is pegged at 100% isn't unusual. You should be looking at the frame rate it is transcoding when at 100%. If, for example, you were transcoding at 300 FPS hypothetically you could support ~10 simultaneous transcodes if the video is 24FPS. Leaving yourself a little extra headroom to ensure things remain responsive.