PhotoFlashDrive only uses high-quality NAND flash memory. The read and write speeds will vary from drive to drive, or batch to batch, depending on which USB controller and NAND flash are used.
The write speed of a 2.0 USB can be as slow as 4MB per second (4MB/s) and as fast as 8MB/s. A 10GB file loading at 4MB/s would take roughly 40 minutes; loading at 8MB/s would take roughly 20 minutes.
USB 3.0 improves these times by up to 10x depending on many variables making the write speed be 10MB per second to as much as 35MB/s.
The read speed on a USB 2.0 is much faster than the write speeding ranging from 15MB/s to 30+ MB/s.
Again, a USB 3.0 drive will be faster with a read speed of 75 MB/s to 110+ MB/s