NVMe stands for Non-Volatile Memory Express.
- It is a communication protocol designed specifically for fast storage devices like SSDs.
- It replaces older protocols like SATA and AHCI, which were originally built for slower spinning hard drives (HDDs).
- NVMe works over the PCIe (Peripheral Component Interconnect Express) bus, which provides much faster data transfer rates than SATA.
NAND Flash as the storage technology
Although NVMe SSD often use NAND Flash, they are much faster than non-NVMe NAND Flash SSD. Some of the newest NVMe SSD use 3D Xpoint or Optane as a storage technology
How Fast is NVMe Compared to SATA SSDs?
| Feature | SATA SSD | NVMe SSD |
|---|---|---|
| Interface | SATA III (6 Gbps, ~600 MB/s) | PCIe Gen 3, 4, or 5 (up to 16 GB/s for Gen 5) |
| Latency | ~30-100 microseconds | ~2-10 microseconds |
| Max Bandwidth | ~600 MB/s (SATA III limit) | 3.5 GB/s (PCIe Gen 3 x4), 7 GB/s (PCIe Gen 4 x4), 15+ GB/s (PCIe Gen 5 x4) |
| Command Queue | 32 commands (AHCI limitation) | 64,000 commands per queue and 64,000 queues |
Why is NVMe Faster?
- Direct PCIe Connection:
- NVMe uses the high-speed PCIe bus, bypassing the slower SATA interface.
- Optimized Protocol:
- NVMe was built specifically for SSDs, unlike SATA, which was originally designed for spinning hard drives.
- Parallelism:
- NVMe supports a much larger number of commands and parallel operations, leveraging modern multi-core CPUs and SSDs’ internal architecture.
Real-World Performance
- A high-end SATA SSD might read/write at ~550 MB/s.
- A PCIe Gen 4 NVMe SSD can reach ~7,000 MB/s, making it 10-12x faster.
- PCIe Gen 5 NVMe SSDs can surpass 14,000 MB/s, making them even faster.
Conclusion
NVMe is far superior to traditional SSDs using SATA in terms of speed and efficiency, especially for applications like gaming, video editing, or high-performance computing.