SSD vs NVME vs M.2 – Difference and Comparison

What is SSD?

An SSD, also known as a solid-state drive is a storage device that uses integrated circuit assemblies to store data persistently. Unlike a Hard disk drive, a solid-state drive stores data semiconductor cells rather than a rotating disk.

SSD means mSATA SSD or 2.5” SSD, which is the first generation of SSD. Compared with hard drives, SSDs are more resistant to physical shock and have higher input/output rates. Another improvement from HDD is SSD makes no sound and has lower latency.

The 2.5” SSDs connect to the motherboard via SATA and transfer speeds max out at around 550 MB/s.

SSDs based on NAND flash can slowly leak charge over time if left powerless for a long time. This may cause worn-out drives.

What is NVMe?

NVMe, also known as Non-volatile Memory express Specification is an open, logical-device interface specification for accessing a computer’s non-volatile storage media. They are attached via PCI Express bus.

“Non-volatile” memory indicates that to retain information, they don’t need to be powered. Volatile memories, like RAM, require an active power input to retain information.

NVMe SSDs are a recent technology, debuting in 2013.

An NVMe drive delivers a sustained read-write speed of 3.5 GB/s. Some Gen 4 NVMe PCIe SSDs are capable of exceeding 7.5 GB/s

What is M.2?

M.2 is a specification for internally mounted computer expansion cards and associated connectors. It was previously known as the Next Generation Form Factor (NGFF).

M.2 replaces the mSATA standard, which uses the PCI Express Mini Card physical card layout and connectors.

As M.2 is a form factor, both SATA and NVMe SSDs can be an M.2 SSD. But typically, an M.2 SSD means SATA SSD with M.2 form factor. Like any other SATA SSD, M.2 SSD can read and write data at a maximum of 550 MB/s.

But they are more slim and compact in size than 2.5” SATA SSD.

Difference Between SSD and NVMe and M.2

SSDs have significantly slower transfer speeds when compared to NVMe due to bottlenecking of the SATA connection protocol. They are larger in size than M.2 form factor. M.2 SSD s are more compact than SATA SSD, but still fall behind NVMe due to its SATA connection protocol.

Both SATA 2.5” SSD and M.2 SSD can read and write up to the speed of 550 MB/s. NVMe, on the other hand, can read/write at 3500 MB/s at a PCIe 3 connection and can reach 7500 MB/s at a PCIe 4 connection.

SATA SSDs are compatible with almost any motherboard. M.2 SSDs require an M.2 slot. NVMe SSDs require an M.2 slot that supports NVM express. In most motherboards, there are two M.2 slots. One of them supports NVMe and the other is M.2.

The NVMe slot can support both NVMe and M.2, but M.2 slot doesn’t support NVMe. SATA SSD requires a SATA cable and SATA port.

The SATA SSDs are the cheapest option. M.2 SSDs are costlier than SATA. NVMe is more expensive

Comparison Between SSD and NVME and M.2

Parameters of ComparisonSSDNVMeM.2
ConnectorSATAM.2SATA
Connection ProtocolSATAPCIeSATA
TechnologySATANVMeSATA
Form factor2.5M.2M.2
SpeedMaximum 550 Mb/s3500 MB/s in PCIe 3, 7500 MB/s in PCIe 4Maximum 550 Mb/s

References

  1. Performance Analysis of NVMe SSD-Based All-flash Array Systems | IEEE Conference Publication | IEEE Xplore
  2. NVMe vs. M.2 Drives: Which SSD Is Right for You?