ffmpeg transcoding not using maximum resources

[Spyderturbo007]

I'm not really sure where this should go.  I've posted on the Emby forum, but haven't really gotten anywhere.  I don't know if this has to do with Emby, unRAID or ffmpeg.

 

I'm trying to transcode (on the fly) 4K video using Emby.  The server has 2 x 16 core Opteron 6380 CPUs so according to the passmark scores, it should be able to handle at least one 4K transcode.

 

My problem is that the transcode starts at around 41fps and then slowly degrades down to ~22fps.  Once that happens the transcode buffer is overrun and the stream stutters.

I'm asking here because the CPUs are really just sitting there waiting for something to do.  It's not like they are all maxed out at which point I would say, "Hey, this thing just can't handle it".   Here is what the usage looks like at 22fps.

 

I'm just asking here since I'm not really sure where to look....

 

 

Edited December 12, 2020 by Spyderturbo007

[Spyderturbo007]

Just thought I'd see if anyone had any thoughts?  I'm not getting anywhere in the Emby forum.