Tried a bunch of method to speed up/buffer the write speed to tape drive in Cygwin. Then found out the pipe itself has performance issues.

With `dd if=/path/to/test/file of=/dev/nst0 bs=4M`, it can easily get 160MB/s writing speed. But with `dd if=/path/to/file bs=4M | dd of=/dev/nst0 bs=4M status=progress`, I can only get about 65MB/s.

That's not usable.