Hello XORROR,
I have branched your comment to a new thread in the /community/tech/solidstate/content Solid State Drives Community, since the issue was different from the original topic of the thread.
The model numbers SSDPEDMW400G4X1 and SSDPEDMW400G4R5 are both for the Intel® SSD 750 Series 400GB, 1/2 Height PCIe 3.0 Add-in-card.
The difference in the last two digits, X1 vs R5, is for the original packaging from factory. SSDPEDMW400G4X1 is a single pack and the SSDPEDMW400G4R5 is the reseller 5 pack. Retailers normally sell any of the two model numbers individually, but the SSD itself will have the same size and form factor.
