5 primary options available
M.2 SATA SSDs
The newer M.2 form factor is more compact than the 2.5-in. SSD and offers a choice of SATA or NVMe interface. M.2 drives are 22mm wide and may be 30mm, 42mm, 60mm, 80mm or 110mm long. M.2 SATA SSDs, like the Samsung 860 EVO M.2 SATA, offer the smaller form factor that goes with M.2, but with the less expensive SATA interface — ideal for applications where the highest level of performance is not necessary.
The 2.5-in. SATA SSD is now in its fourth generation, and comes with improved speed, originally at 100 MB/s, now 300 MB/s to 550 MB/s or better — typically at the maximum that the SATA interface will allow. Longevity of the drives are much longer than that the first generation SSDs, which may only last a year or two. A typical 2.5-in. SSD is the Samsung 860 EVO as well as the Samsung 860 PRO.
M.2 NVMe SSDs
The latest type of SSD available is the M.2 NVMe SSD. It combines the faster NVMe interface with the compact M.2 form factor. It offers high levels of performance, with up to 3,500 MB/s throughput and up to 400,000 IOps, along with lower power consumption and more efficient power usage than the 2.5-in NVMe. One example of a typical M.2 NVMe SSD is the Samsung 970 PRO, Samsung 970 EVO Plus.
mSATA SSDs use a compact format similar to M.2, but with a 30mm width and 50.95mm length. These drives are uncommon, primarily being used in some tablets and notebooks where space is at a premium. A typical mSATA SSD is the Samsung 860 EVO mSATA. The mSATA and 2.5-in. SATA SSDs typically have very similar performance statistics — about 550 MB/s for sequential reads in the 860 EVO, and 520 MB/s for writes. There are also mPCIe cards, which use the same connector as the mSATA, but connect to a PCIe host controller or USB controller, rather than a SATA controller.
2.5-in. NVMe SSDs
The 2.5-in. NVMe SSD offers the ability to go faster than the SATA bus can support. By using the newer NVMe standard (with the latest spec being NVMe 1.3a or 1.4), drives can sustain throughputs as high as 3,500 MB/s, compared to the 550-600 MB/s that the SATA bus supports. Input/output operations per second (IOps) are also as much as ten times higher, going from around 50,000 IOps in a SATA drive to as many as 500,000 IOps with NVMe. A typical 2.5-in. NVMe SSD is the Samsung 983 DCT, which looks like a 2.5-in. SATA SSD but operates with an NVMe interface and performance.
Which one’s right for your device?
When buying your next SSD, keep in mind the device you’re seeking to upgrade, whether it’s a laptop, desktop or server. Here’s a further breakdown on how to evaluate for each: