Running plex on windows10
Processor Intel(R) Core™ i7-3770 CPU @ 3.40GHz, 3401 Mhz, 4 Core(s), 8 Logical Processor(s)
Name NVIDIA GeForce GT 730
8TB SSD samsung storage 256m ssd system
16 gig ram
From reading before i built this it should be overkill to stream 3 sessions, but transcoding to lan from 4K to 1080 1 session pegs cpu to 100% 30% on GPU using HW for both decoding and encoding. Is the audio killing the PC?
As @TeknoJunky states, your system is not powerful enough to transcode 4K HEVC video.
The i7-3770K is not powerful enough to transcode 4K in software (Ref 1, Ref 2).
The Intel HD Graphics 4000 in the i7-3770K does not support decoding HEVC video (ref).
The GT 730 does not support decoding HEVC video (Ref).
HDR to SDR tonemapping is compute intensive, and Plex does not support tonemapping on Nvidia GPUs with Windows 10 (Ref).
If you want to transcode 4K HEVC HDR video in Plex you will need to replace your Plex Media Server. You’ll need a 7th gen or later Intel CPU (for HEVC 10-bit decoding) preferably running Linux (for tonemapping support).