how can find speed of pen drive?

To find the speed of a pen drive, you can use a computer with USB ports and a file transfer test. Copy a large file (such as a video or a folder of files) to the pen drive and measure the time it takes to complete the transfer. Alternatively, you can use software tools like CrystalDiskMark or USBDeview, which can provide detailed benchmarks of the pen drive's read and write speeds. These methods will give you a good indication of the pen drive's performance.