iMac mid 2011 27 inch - External SSD USB extremely slow

Hi All

I have recently upgraded the internal drive to SSD and that works like a charm read and write speed around 450mb but I have also bought a external SDD and unfortunately that is extremely slow please see attached the max read and write speed it gives via USB, does anyone else have similar issues?

BTW I have tried the external SSD on a 2015 macbook pro and gets around 400mb speed to that rule out the possibility that drive is faulty.

Thanks in advance