WD MY BOOK Pro Read / Write Speed on iMac Pro - slow

I’ve recently upgraded my iMac 2013 to an iMac Pro.

Previously on my WD My Book Pro over a Thunderbolt 1 connection I was getting approx
230mb/s write
286mb/s read

Having upgraded to the iMac Pro with a Thunderbolt 3 to Thunderbolt 2 adapter plus Thunderbolt 2 cable I am still seeing the same speeds…

In reviews I have seen the Thunderbolt 2 speeds listed in the 380mb/s - 420mb/s.

Any tips on solving this, or diagnosing my problem?

Hi domx360,

I would suggest to check R/W speed using other USB cable or with thunder bolt cable. You may also diagnose the health of My Book Pro using WD Drive Utilities.