DS423+ Transcoding

[NasNoob]

I have a DS423+ used primarily as a Jellyfin media server. I selected this model as I thought (hopefully not incorrectly) that the CPU was suitable for server side transcoding. However, I am noticing that certain .mkv files (I believe HEVC 10) are causing 80% or more CPU load during playback. What am I doing wrong? 

I have Jellyfin installed through the community app store (as opposed to docker). Maybe my Jellyfin playback settings are the issue? Is there a software tweak I am missing to optimize my setup? 


Settings: 
Hardware Acceleration - Intel QuickSync
Enable Hardware Decoding for:
   - H264
   - HEVC
   - HEVC 10bit
   - VP9 10bit
   - Prefer OS native DXVA or VA-API hardware encoders
Enabled hardware encoding
Allow encoding in HEVC format
Enable VPP Tone mapping
   - VPP Tone Mapping brightness gain: 16
   - VPP Tone Mapping contrast gain: 1
Enable Tone Mapping:
   - algorithm: BT.2390
   - mode: auto
   - range: auto
   - desat: 0
   - peak: 100
   - thread count: auto
H.265 encoding CRF: 28
H.264 encoding CRF: 23
Deinterlacing method: YADIF
Throttle Transcodes: Yes


Appreciate any help I can get!