Dont understand the technical side, but beware some MBs have just patched on an M.2 socket.
You absolutely need to check that little flow diagram and see what its connected to!
You need the proper PCIe one.
I backed out of the M.2 drive when I saw they run at 100C , samsung 950 Pro is the best or 110C for the older one.
Similar ( but not quite as much ) performance can be got from the Intel 750 PCIe aic ( nice big heatsink )
Look at Puget systems review on the samsung 950 pro with a heat camera ... Scary 100C in 50 seconds right by the socket connector. :-/
I initially got An Asus x4 PCIe to M.2 adapter card - as a buffer - so that heat is kept well away from my motherboard. The system just sees it as a PCIe card ( no software no drivers
). Seemed to work, but I was convinced by a really knowledgable guy, who explained "in the real world of usage ... IF your MB has the right architecture, then the Intel will perform every bit as fast as the Samsung 950 Pro".
... Is he right
All I can say is I loved my Samsung 850 Evo, and now ADORE the Intel.
My assessment is not based on uber technical read write benchmarks ... But what I see with my own eyes. Booting up in seconds , loading files, copying a shoot...say 32GB of pics from one drive to the other.
Loading a days shoot of 5DS R's images say 800 images into DPP is now instantaneous! Click bang they are all there (one is able to click on any image immediately and explode it to edit) , on my old system you could sod off and make a cuppa before they all appeared, let alone be able to edit them.
I am delighted with Intel 750 but wish the 800GB varient was as fast as the 400gb and 1200GB versions ( I could not justify the cost of the 1.2TB one. )
Anyway 400GB is almost, just about big enough for Windows 10 and my software ( MS Office, Photoshop Element And Premier and Canon DPP with Portraiture. And a couple of shoots.... 
I see folks saying 250GB is enough ... Imo that would be a total pain in the axxx. How they manage with that Imdont know as its filling up with a few shoots. Bit then do the have the burden of 5DSRs file sizes.
I now have as a work around, a sort in Interim storage disc a samsung 850 500GB SSD to offload a shoot worths, after I have finished the initial edit.
An ideal size IMO would have been 800GB and then archive the stuff to HDDs.
It will take maybe 2 mins before I am ridiculed for stating this - but happy to send to a screen shot showing 48 GB free space on a 500GB samsung after a couple of weeks.
If you have say a 5D3 then I rekon a 500GB drive would be fine.
If your MB has the lanes ( mine does 
) then boy does it fly! Blows away the samsung 850 evos. And they are great.
I wouldn't consider a new system without this technology, after all, you can take all this kit to your next build.
Canon EOS 5DS R, Canon EF 70-200 F2.8 L Mk II IS USM, Canon EF 70-300 F4-5.6 L IS USM, EF 40mm F2.8 STM , RC6 Remote. Canon STE-3 Radio Flash Controller, Canon 600 EX RT x4 , YN 560 MkII x2 ; Bowens GM500PRO x4 , Bowens Remote Control. Bowens Pulsar TX, RX Radio Transmitter and Reciever Cards. Bowens Constant 530 Streamlights 600w x 4 Sold EOS 5D Mk III, 7D, EF 50mm F1.8, 430 EX Mk II, Bowens GM500Rs x4