I'm running quad-channel 4 x 8 GB 4000 MHz C17 so memory bandwidth is not a problem. The CPU usage stays the same as 8-bit at around 14%, but 10-bit stutters severely.
Here is my MPV configuration.
# this is required for SVP to "catch" the mpv
input-ipc-server=mpvpipe
# hardware video decoder
hwdec=d3d11va-copy
hwdec-codecs=all
vo=gpu
gpu-api=d3d11
gpu-context=d3d11
# high quality video output, require rather fast video card
profile=gpu-hq
# use ANGLE if you have problems with default d3d11 renderer
#gpu-context=angle
# OR the newest VULKAN API
#gpu-api=vulkan
# miscellaneous options
# fixes audio desync
hr-seek-framedrop=no
# this can't be used with SVP cause it also saves vf's states
save-position-on-quit=no
# "ReClock" replacement
#video-sync=display-resample
#video-sync-max-video-change=5
#log-file=mpv.log
ao=wasapi
audio-exclusive
audio-spdif=ac3,dts,dts-hd,eac3,truehd