slow read speed cache drive

[ikosa]

if i copy a file from transmissions (running from docker) downloaded folder to a disk share (with mc) or my windows desktop it copies around 8-15 MB/s. (file is not seeding)

but if i copy that file into root of my cache only share and try to copy from there it copies around 40-50 MB/s.

i cant figure out why. This issue dramaticly slows down my mkv muxing process for finished downloads.