What is NVMe?
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Short answer
NVMe (NVM Express) is an interface specification for solid-state drives that talk to the computer over PCI Express — not a form factor and not a separate kind of storage from “SSD”. The NVM Express organisation describes it as “an interface specification optimized for PCI Express based solid state drives” (NVM Express FAQ). An NVMe drive is an SSD; NVMe is how the host and the drive exchange commands and data.
This page explains what NVMe is. If you are choosing between interfaces, use NVMe vs SATA (including the M.2 vs NVMe section there).
Protocol, bus and shape
| Term | What it is | Primary source |
|---|---|---|
| NVMe | Host controller interface / command set for non-volatile memory over a transport (commonly PCIe) | NVM Express FAQ; NVMe over PCIe Transport |
| PCI Express (PCIe) | High-performance serial I/O interconnect with 1–32 lanes | PCI-SIG |
| M.2 | Card / slot form factor (e.g. 2280) — may be wired for SATA, NVMe, or both | Motherboard / device manual; PS5 accepts NVMe only, not M.2 SATA (Sony) |
| SATA | Older storage interface, 6 Gb/s | SATA-IO Revision 3.0 |
NVM Express originally defined how host software talks to non-volatile memory across a PCIe bus; the PCIe-specific mapping now lives in its own transport specification so the base command set can stay transport-agnostic (NVM Express).
Why NVMe ratings dwarf SATA
A SATA 6 Gb/s link cannot carry much more than about 600 MB/s of payload after encoding, which is why current SATA SSDs are rated near 560 MB/s sequential (example: Samsung 870 EVO, datasheet).
PCIe scales with generation and lane count. PCI-SIG lists raw bit rates per lane per direction, including:
- PCIe 3.0: 8.0 GT/s
- PCIe 4.0: 16.0 GT/s
- PCIe 5.0: 32.0 GT/s
A PCIe 4.0 x4 drive such as the WD_BLACK SN850X is rated up to 7,300 / 6,300 MB/s sequential read / write (Sandisk). Those are manufacturer “up to” figures, not our measurements.
What NVMe is not
- Not a guarantee of an M.2 slot. Some M.2 slots are SATA-only.
- Not a substitute for capacity or TBW. Endurance and size are model properties; the 1TB 870 EVO and 1TB SN850X both list 600 TBW.
- Not the same as “PS5 SSD”. The PS5 requires a PCIe Gen4 x4 NVMe M.2 (Key M) drive, recommends ≥ 5,500 MB/s sequential read, needs a cooling structure, and does not support M.2 SATA or Host Memory Buffer (Sony).
FAQ
What does NVMe stand for? NVM Express — Non-Volatile Memory Express; informally NVMe (NVM Express FAQ).
Is NVMe the same as M.2? No. M.2 is the shape; NVMe is the protocol. See the dedicated section on NVMe vs SATA.
Can I plug an NVMe SSD into a SATA cable? No. NVMe needs a PCIe-wired M.2 slot (or a suitable adapter).
Related pages
- NVMe vs SATA — choosing an interface (includes M.2 vs NVMe).
- M.2 slot guide
- How to install an SSD · Laptop SSD upgrade