Question Flash memory speed issue

[drjackool]

Hi
I today bought an A-DATA UV350 USB 3.2 flash drive (128GB) and formatted it with NTFS file system. problem is when coping file to it the speed is not constant and drop to zero periodically! is this normal or I should return the flash drive?
My mobo is Maximus X hero wifi and I connected the flash drive to back panel USBport red color

 

[Darkbreeze]

Most likely, it's normal. They get very hot, very fast, and when they do they throttle themselves. Then they cool fairly rapidly as well, burst again, throttle. Every flash drive I've ever owned, especially newer ones that have pretty fast specs, does this. Especially if you are transferring rather large files TO the flash drive. Prolonged transfers will see more of this behavior than transfer of smaller files.