In planning my build, I'm reading up on Samsung 960EVO M.2 SSD (I'm looking at 500GB -- $250) for use as C: boot drive. "Boot from" M.2 SSD is only supported by a few motherboards.

Why bother? 960EVO delivers up to 3.2GB/s read and 1.9GB/s write -- up to 600 percent as fast as a standard fast SSD. Random Read/Write is 400 percent as fast. 960EVO plugs into a small PCIe type slot. Thing is, to boot the PC from an M.2 SSD, the chipset, socket, and BIOS have to support "boot from M.2".

Right now I'm zeroing in on "ASUS Crosshair VI Hero" or "GIGABYTE AORUS" motherboards in the $220 to $250 "expected" price range (some versions will cost more others will cost less). Because these are high end, new design motherboards, I imagine they support M.2 SSD boot -- but, we'll see when they go on sale in 3 days (3 days is the rumor).

EDIT: After searching around the internet, the above MBs and others seem to support M.2 at 3.2GB/s. So, I've ordered a 960EVO. All I need now is a Motherboard, Ryzen, and probably a new "motherboard attachment piece" for my CPU water cooler to complete my build (much is being transferred from my current setup).