WD Passport 4tb just purchased! It is slow

I brought a new hard disk 2days ago. But It’s slow I think. file transfer speed should be 100mb/s. But I got 35-42mb/s.
What Should I do?

File transfer speed is only going to be 100MB (not mb)/second under very specific circumstances – like if you’re writing one very large file with little to no fragmentation.

If you’re writing lots of small files, performance will drop. That’s the same for any drive, not just WD’s.

Of course, it also will be dependent on the source of the data you’re writing.

By the it’s a typing mistakes. I was transferring a video. I didn’t transfer a lot of small file. I want to know that is this problem with my drive or it is wd my passport transfer speed?

But from where was that video copying FROM? The task manager screenshot seems to indicate it’s not coming from your C drive…

That could be the drive is Shingled magnetic recording (SMR). SMR drives 2.5" are tend to write slower. If you want to know what SMR drive is search on wiki for more info.