Volatile transfer speeds between shares

[theuema]

Hi,

 

I do encounter quite unsatisfying behavior in terms of volatile speeds when copying or moving files from one share to another using rsync.

Please view my attached screen recording.

In this case, i was copying a 16Gig, or so, file between shares.

The source share is located on the same physical HDD than the destination share.

 

Speeds range from <1 MB/s to >200MB/s, always going up and down, like some super-fast cache gets filled up and the HDD can not handle all the incoming data.

 

Does anybody have a better explanation or encounters the same when copying via. ssh/rsync?