[WorldStudios]

Originally Posted by Darryl Ramm

Your Mac Pro has a PCIe 2 not PCIe 3 slots and the NVMe m.2 card you have is PCIe 3. You are running it at half speed. You need to look for a switch based PCIe 2 x 8 adapter card that switches down to PCIe 3 x 4.

Thanks, that sounds about right. Do you know of any such adapters that work in a 2012 MacPro?