I tested a 4k full bluray HDR 10bit with DTS-HD 60gb. On a t95x s905x the device has trouble to stay in sync with audio and sometimes it eve loses audio output. It only restore by reopening the file... i play the file via ethernet 100mbit from NAS
File info? I have a few 10 bit 2160p hdr10 files around that size that work well, all 23.976fps, and I do audio passthrough with hdmi. For 60fps I haven't played longer than test files, so can't comment (I know there's one "high framerate" 60fps movie out).
BTW: if you're 10bit/hdr capable, you shouldn't be using krypton which is incapable of full 10 bit video output (can do 10 bit output, but video is cut down to 8 bit first resulting in banding).
Edit: because of guy below me, I also use network, but don't use samba. If you're okay on external drive, maybe try a different network protocol with less overhead?