It is 2024 and people are still confused about M.2 drives. There are two types of M.2 drives. M.2 NVMe and M.2 SATA. Because both are based on M.2 form factor, the confusion is obvious. Both drives look exactly the same. But, there are many differences to uncover just by paying a little attention.
To start with the difference, the performance difference between the both is huge. M.2 NVMe drives have a larger bandwidth through PCIe lanes for data transfer. These drives connect directly to the CPU. On the other hand, the M.2 SATA drives use the SATA interface which has the maximum bandwidth of 6 Gbps or around 750 MB/s (theoretical) In the real world, it is just 550 MB/s. The SATA interface was actually designed for hard drives and is controlled by the chipset on the motherboard i.e. no direct connection to the CPU.
The biggest advantage of the M.2 NVMe drives is that they can evolve with the growing PCIe generations. For example, the NVMe drives have the bandwidth when the system has PCIe 4.0 to PCIe 5.0 capabilities. This way, these drives have room to reach speeds up to 14,000 MB/s.
With the smaller form factor, the M.2 SATA drives have the obvious advantages of space and power consumption. Otherwise, the normal 2.5″ SATA and M.2 SATA drives are the same.
The main difference: Performance
There is no comparison when it comes to the performance we get from both these drives. M.2 SATA drives are way behind even the Gen 3.0 NVMe drives, let alone the Gen 4.0 and 5.0. Here is a detailed table of theoretical performance differences between M.2 NVMe vs M.2 SATA SSDs.
| Specification | M.2 SATA | M.2 NVMe (PCIe Gen 3) | M.2 NVMe (PCIe Gen 4) | M.2 NVMe (PCIe Gen 5) |
|---|---|---|---|---|
| Interface | SATA III | PCIe 3.0 x4 | PCIe 4.0 x4 | PCIe 5.0 x4 |
| Theoretical Bandwidth | 6 Gbps (750 MB/s) | 32 Gbps (4 GB/s) | 64 Gbps (8 GB/s) | 128 Gbps (16 GB/s) |
| Typical Sequential Read Speed | ~550 MB/s | ~3,000 MB/s to 3,500 MB/s | ~5,000 MB/s to 7,500 MB/s | ~10,000 MB/s to 14,000 MB/s |
| Typical Sequential Write Speed | ~500 MB/s | ~2,500 MB/s to 3,000 MB/s | ~4,000 MB/s to 7,000 MB/s | ~9,500 MB/s to 13,000 MB/s |
| Random Read IOPS | ~95,000 | ~350,000 to 500,000 | ~700,000 to 1,000,000+ | ~1,500,000 to 2,000,000+ |
| Random Write IOPS | ~85,000 | ~300,000 to 450,000 | ~600,000 to 1,000,000+ | ~1,400,000 to 2,000,000+ |
| Latency | ~50 µs | ~30 µs | ~20 µs | ~10-15 µs |
| Power Consumption | Low | Moderate | Higher | Highest |
Talking about the same Form Factor (M.2)
Both the drives come in the same form factors. The 2280 form factor is the most common one while you can see many laptops with the smaller 2230 and 2240 NVMe drives. The 2260 and 22110 are the rarest form factors.
| Form Factor | Dimensions (Width x Length) | Keying | Interface | Typical Uses |
|---|---|---|---|---|
| M.2 2230 | 22mm x 30mm | B, M, or B+M | SATA or PCIe | Ultrabooks, tablets, and small devices where space is limited. |
| M.2 2242 | 22mm x 42mm | B, M, or B+M | SATA or PCIe | Compact laptops, mini PCs, and embedded systems. |
| M.2 2260 | 22mm x 60mm | B, M, or B+M | SATA or PCIe | Mid-range laptops, desktops with space constraints. |
| M.2 2280 (Most Common) | 22mm x 80mm | B, M, or B+M | SATA or PCIe | Standard for most consumer laptops, desktops, and workstations. |
| M.2 22110 | 22mm x 110mm | M | PCIe (NVMe) | High-performance workstations, enterprise servers. |
In the illustration, I have added the B-Key SATA SSD which is very rare now. You will just see the M.2 NVMe SSDs with on notch on the right side and the M.2 SATA SSDs with two notches on the left and right.
Compatibility
The M.2 NVMe ports on the motherboard would support both NVMe and M.2 SATA SSDs. The speed will be as per the drive’s performance. However, if the port is M.2 SATA-only i.e. it just has SATA lanes allocated to it, an M.2 NVMe would not work on it.
Physically, the M.2 NVMe port would support an M.2 SATA drive. But, if the port has two slots for (B+M Key) SATA SSD, the M.2 will not fit inside it.
Cost
The M.2 SATA SSDs are cheaper and offer larger storage space at easy prices. However, M.2 NVMe drives can be pretty expensive depending on their brand, generation, and performance.
The M.2 SATA or 2.5″ SATA offers a good price-to-capacity ratio. On the other hand, the M.2 NVMe drives offer a good price-to-performance ratio. The SATA drives are well suited for bulk data storage on high-end computers. They work well with low-end systems as primary storage devices. However, M.2 NVMe drives can remove storage bottlenecks and empower the already-powerful systems.
Power Consumption and heat generation
M.2 SATA SSDs generally consume 2 to 4 watts during active read/write operations. On idle mode, it can come down to just 1 watt. This can be beneficial in improving battery life in portable devices. These drives generate less heat because the work done is lower over time. So, there is always less current flowing inside the circuits as compared to the NVMe drives.
NVMe drives up to Gen 4.0 and can consume between 5 to 8 watts under heavy read/write loads. Even on idle modes, you can expect a power consumption between 2 to 3 watts. Also, the heat generation is high. Most companies are offering their heatsink variants with Gen 4.0 and 5.0 NVMe drives. In fact, there are setups for active cooling through water pumps and air coolers.