i use NVS 2081 + with Seagate ST2000LM015. No matter which type of memory card I use (XQD over sXs, SD, CR over Cardreader. Sometimes copy goes slow for some files und then moves on fast. In summary it reduce the speed of copy from card to HDD. I've tryed a second HDD some type - with the same result.
Using SSD there is no problem.