Volume or Partition for iMac Fusion Drive

[jdc]

Not to throw a wrench into things, but for most all uses, the Fusion drive is faster than your 2.5" SSD, by a quite a bit.

if you really want to speed things up... with your new USB C ports its time to upgrade your SSDs to flash drives... assuming you connecting it to the USB C and not USB A port... of course that would requrie also getting drive adapters.

Scratch that -- looks like all the adapters are limited to slower SATA speeds.