Very slow i/o to external hard drive's HFS+

[Rob Stevens]

Hello

I have a removable hard drive sporting an HFS+ connected to a USB3 port.
The drive is a Seagate Slim Line 2T.
I am using a driver from Paragon Sofware to write/read from this drive.
I am running Windows10 build 19041.508 (ie up to date)

Writing to this file system using the unix cp command is incredibly slow:

cp my_file /cygdrive/h/some_destination
The same write, using copy paste in Windows Explorer is much faster.

I have not precisely timed it, but it is way more than an order of magnitude
faster (a 1G file took approx 10 mins: the graphical display shows just
a few seconds).

(In Windows Device Manager I have the policy for the drive set to be
"Better Performance"  and not "Quick Removal" -- apparently
the latter can lead to dramatic degradation in performance).

Can anyone suggest what might be the cause?

Rob Stevens