Hi There - question for you - I am running a very similar configuration - i7 skull canyon nuc so a bit older - 32 gigs of ram 970 evo m.2. I thought it would make for a pretty good plex build and so far I have to say I am pretty happy with it. And while I am not running Ubuntu, I am running CentOS 7.7.1908 - So a couple of observations I was hoping to run by you.
A) I can run one 4k transcode (from HEVC 10bit) and keep the load at or around ~4. A second one pushes things past 10 and both streams begin to stutter and the experience becomes dull.
B) Every once in a while - the whole system will lock up, I’ve got it sitting on one of those laptop coolers for the additional air flow but neverthless I am seeing this in dmesg (below). I just wanted to share my experiences with you and see what if any improvements you might have made to optimize performance on your NUC.
Thanks!
[65547.139561] CPU6: Package temperature/speed normal
[65547.139563] CPU2: Package temperature/speed normal
[65547.139575] CPU1: Package temperature/speed normal
[65547.139577] CPU5: Package temperature/speed normal
[65547.139590] CPU7: Package temperature/speed normal
[65547.139593] CPU3: Package temperature/speed normal
[65547.139608] CPU4: Package temperature/speed normal
[65547.139612] CPU0: Package temperature/speed normal
[65857.884509] CPU4: Core temperature above threshold, cpu clock throttled (total events = 22858)
[65857.884510] CPU0: Core temperature above threshold, cpu clock throttled (total events = 22862)
[65857.884512] CPU0: Package temperature above threshold, cpu clock throttled (total events = 57710)
[65857.884546] CPU1: Package temperature above threshold, cpu clock throttled (total events = 57701)
[65857.884547] CPU6: Package temperature above threshold, cpu clock throttled (total events = 57715)
[65857.884548] CPU5: Package temperature above threshold, cpu clock throttled (total events = 57709)
[65857.884549] CPU3: Package temperature above threshold, cpu clock throttled (total events = 57715)
[65857.884550] CPU7: Package temperature above threshold, cpu clock throttled (total events = 57715)
[65857.884551] CPU2: Package temperature above threshold, cpu clock throttled (total events = 57715)
[65857.887701] CPU4: Package temperature above threshold, cpu clock throttled (total events = 57712)
[65857.911719] CPU1: Package temperature/speed normal
[65857.911720] CPU4: Core temperature/speed normal
[65857.911721] CPU0: Core temperature/speed normal
[65857.911722] CPU7: Package temperature/speed normal
[65857.911723] CPU2: Package temperature/speed normal
[65857.911724] CPU5: Package temperature/speed normal
[65857.911724] CPU6: Package temperature/speed normal
[65857.911725] CPU3: Package temperature/speed normal
[65857.911726] CPU4: Package temperature/speed normal
[65857.911726] CPU0: Package temperature/speed normal
