What you need to do before you ever format a usb drive is copy down its current structure and information about alignment and such. Then duplicate the structure and alignment using a formatting tool. If you don’t know how to do that, you shouldn’t be reformatting it.
Regardless, here’s a snapshot of of what the original factory default structure is like of a sandisk extreme usb 3.0 64GB drive
Use something like gparted (http://gparted.org/)) and make 32K block size, align to 32K, start of the partition should be at 32K as well.
If the drive is still slow try doing a full format, not a quick format.
