M.2 SSDs: Common Questions and Important Differences

What is the difference betwen SATA and PCIe M.2 drives? The main difference is that PCIe and SATA M.2 drives have different controllers. PCIe is the faster of the two. SATA will generally be compatible with a wider variety of systems, and is better supported in older models. If a system has an M.2 PCIe slot,  an M.2 SATA SSD with identical keying will fit in the slot but will not work, and vice versa. There are some systems that are dual-mode, and will accept both SATA and PCIe drives.

What’s the difference between the 2260ds and the 2280ss? These numbers determine the physical size of the M.2 drive. A 2260 would be 22mm wide and 60mm long, while the 2280 would be 80mm long. Some systems will also support multiple lengths of M.2. We currently offer the 2280 variant in our M.2 SSDs. The ‘ds’ and ‘ss’ signify either double-sided or single-sided, referring to how the NAND is placed on the circuit board.

How much does the key notch matter? In the case of Crucial's PCIe SSDs, our drives are M-keyed only, meaning they will not be able to fit in a B-keyed slot (which is generally used by SATA M.2 devices). Our SATA M.2 devices are both B- and M-keyed for maximum compatibility.

Always make sure to use our Crucial Memory Advisor or System Scanner to verify compatibility of our SSDs with your system. These take all the guess work out of the equation by using our tools to do the work for you. If you have any further questions, be sure to contact our support.