Universal Media Server | Forum

Config:
Windows Home Server 2011
8GB RAM
AMD Phenom II - 965

When transcoding 1080 MKV files, FFMPEG does not build up any buffer. If it is a high datarate movie like Polar Express, it will start stuttering. Processor is only running ~40% load at 80% frequency point when using 'Balanced Power' settings.
If I change to 'Max Performance' Power setting, frequency goes to 100% and buffer starts to build up to 200MB buffer size. Once buffer is full, starts to drop into lower P-states.

It seems FFMPEG doesn't 'load' the processor enough to kick into higher p-state enough to build the buffer while using 'balanced power' mode. It does fine with DVD resolution and lower bit rate bluray movies.
Any thoughts/settings I should try, other than the obvious - leave in 'max performance' power setting...

Sounds strange, is Windows doing the CPU throttling? In any case, it seems whatever is doing the throttling isn't doing a proper job. I hope the algorithm responsible does a better job than monitoring percentage CPU load, as that often isn't very interesting. That is an average per time and per core, so even though you're at 40% you could peak at some cores at times. It still sounds a bit dodgy when there's a buffer involved that it isn't capable of building up the buffer, but I have no idea what (if any) you can do about it.

Maybe you can configure your system so that either UMS or (better) FFmpeg triggers "Maximum performance" state when run, and then falling back to "Balanced" when the program isn't running?