In article ,
RichA wrote:

The hard drives in my computer are fast at transferring data.

nowhere near as fast as an ssd.

Even two
outboard ones I have are. But I got a hard drive caddy from Orico (USB 3)
and it seems stuck at 355kB

KB/s. Exceedingly slow. Shows the same data rate whether plugged into a USB
3 slot or USB 2 slot.
Hard drives used are SATA 7200rpm WD's.

if they're slow without the caddy, then they could be failing.