What’s the difference between M.2, PCIe, SATA, and NVMe for SSDs

There have been a lot of changes in the storage world with the introduction of Solid State Drives, or SSDs for short, not least when it comes to the underlying technologies used to connect these drives to your PC. This means there are a wealth of acronyms to battle with if you’re looking to upgrade the storage on your laptop, desktop, or handheld gaming PC. The good news is we’re here to help you navigate this space and find the right drive for you.

One of the most important things to get your head around when upgrading your storage is the difference between SATA and PCIe. These are two main kinds of SSD interface, which are the physical connections for connecting your SSD to your PC. If your PC, laptop, or device only has a SATA interface, say, then you need a drive that supports that interface if you want to upgrade it.

SATA stands for Serial Advanced Technology Attachment and is the older technology. While it does offer wider compatibility than PCIe, it is showing its age when it comes to performance. The theoretical maximum throughput of the interface tops out at around 550MB/s, where the very latest PCIe 5.0 drives can offer up to 14,000MB/s. That’s almost 25x the throughput. Note that there are two common physical SATA connectors around right now: M.2 and SATA. M.2 drives plug straight into the socket, while a drive using a SATA connector will need a SATA cable.

This brings us to the more recent interface: PCIe, or Peripheral Component Interconnect Express. Quite the mouthful and why we shorten it to PCIe wherever possible. PCIe can transmit data on up to four PCIe lanes, whereas SATA is limited to just one. This inherently gives the newer, PCIe standard, the edge when it comes to throughput. On top of that, PCIe has continued to see improvements with each generation, with the interface almost doubling the throughput each time.

The table below highlights the theoretical maximum throughput supported by SATA and PCIe.

NVMe stands for Non-Volatile Memory Express and is a communication protocol designed to make the most of the how flash memory works. NAND flash is the underlying memory storage technology used in SSDs, so getting the most from it makes sense, particularly as older technologies, such as SATA were designed with hard drives in mind.

Essentially NVMe works better with the parallel nature of flash memory, and when combined with the PCIe interface can offer close to the incredible throughput outlined in the table above. The likes of the CORSAIR MP700 PRO offers read performance up to 12,000MB/s.

If you see M.2 in the description of an SSD then it refers to the physical form factor of the drive. M.2 was introduced in 2012 and was designed to replace the mSATA standard which was briefly popular in laptops. You will generally see numbers following the M.2 that define how big the drive is in terms of its physical dimensions, with two digits for its width and two or three for its length. So, for example, the 2TB MP700 PRO M.2 2280 is an SSD that is 22mm wide and 80mm long.

The M.2 form factor supports a range of widths, but on PC you’ll basically only ever see 22mm wide drives. Until recently the 80mm length was by far the most common as well, at least on desktops and laptops, but the introduction of handheld gaming machines like the Steam Deck, Asus ROG Ally, MSI Claw mean that the M.2 2230 form factor has become more common – we produce a M.2 2230 SSD for such handheld gaming PCs in the form of the MP600 MINI.

Importantly, just because you see that a drive is an M.2 model, that doesn’t mean that it is a PCIe NVMe drive. There are M.2 SATA drives out there as well, and you need to make sure you get the right drive for your system to get the most from it.