NVMe, DRAMless, M.2… What?



I wanted to get a new SSD, and I found a nice M.2 one for cheap, but I don’t understand any of the terminology and I don’t want to make a bad purchase, what does all this mean? I can’t wrap my head around it

In: 7

M.2 is the form factor. That defines the size and shape of the SSD, similar to 2.5” and 3.5” drives.

M.2 drives can electrically connect to the computer through SATA (like most 2.5” drives do) or NVMe. Which one to choose will depend on what your motherboard supports. NVMe can be significantly faster, since it’s designed specifically for the flash memory that SSDs use.

DRAM is literally a little bit of RAM that the SSD uses to speed up reading and writing, especially useful when bursts of activity happen. A DRAMless drive just doesn’t have any.

**NVMe** = The drive interface. This is the “brains” of the drive that lets your computer interact with it. Another popular drive interface is SATA, for example, which your mechanical spinning hard disks likely use. NVMe must be supported by the motherboard and operating system, most modern motherboards and OS’s have this support.

**M.2** = The form factor. This describes the physical shape and layout of the drive and its matching socket. If you want to use a M.2 drive, your motherboard must have a M.2 slot. Make sure this slot is a “Key M” slot, as this is the kind of slot that can fit NVMe drives, as the shape of the connectors on the slot can change depending on what drive interface it supports.

**DRAMless** = this is generally regarded as bad. SSD drives need a sort of address book to tell your operating system where the data physically is. A good, fast drive has a chip called a DRAM chip that stores this address book in a way that makes it very fast to retrieve and use. A DRAMless drive does not have this chip, making it slower (technically it still has the address book, but it is stored in another way that is beyond the scope of this answer). Unlike the previous two items, this will not cause incompatibility, but it WILL make the drive slower. I’d recommend against DRAMless drives if you have the budget.

**PCIe** = You didn’t ask for this but you may find it on product pages. If you see this, it represents the connection interface used by the drive. This is also a part of its brains, but it controls the connection between the drive and your PC. All NVMe M.2 slots and drives function using PCIe, so you shouldn’t worry too much about this one. The only thing to keep in mind is the version: PCIe 3.0 is fast enough, PCIe 4.0 is insanely fast but also more expensive. If either your drive or motherboard do not support each other’s PCIe versions, that’s not an issue as they will automatically fall back to a version supported by both. *(example: if your drive is PCIe 4.0 but your motherboard M.2 slot is PCIe 3.0, they will automatically operate in PCIe 3.0 mode, forgoing the speed bonus of 4.0)*