We've reviewed a few different Silicon Power products in the past and they proved to not only be solid, but affordable as well.  We are hoping the same is true with their latest UD90 Gen4 M.2 solid state drive.  This drive teams the Phison E21 4-channel controller with Micron 176-layer 3D TLC flash.  With this combination the drive boasts read and write speeds of 4800 MB/s and 4200 MB/s respectively.  With a fairly low cost this could be the drive to fully populate the M.2 slots on your new motherboard.  Let's take a look and see what it can do!