One of my USB flash drive (Sandisk 256 GB USB 3.0) is showing quite irregular transfer speeds for larger files (~4GB per file), on my Surface Pro 6. There are no other resource-intensive processes running, and the machine is plugged in. Both the USB flash drive and the Surface's SSD are NTFS formatted.
I am wondering, what could be potential reasons for this behaviour, and are there ways to fix this? Defrag? Driver Update? Shorter File Names? Other performance settings?
These are graphs for one individual 4GB file each: