# Lexar NM620 256GB NVMe SSD Review (2026)

The Lexar NM620 256GB is a budget DRAM-less NVMe drive that trades write speed for affordability, making it a straightforward boot-drive upgrade from SATA.

Quick answer: The Lexar NM620 256GB is best suited as a low-cost boot or OS drive where the 1,300 MB/s write ceiling and 125 TBW endurance are unlikely to matter. Content creators and gamers who regularly move large files should step up to the 512GB or 1TB variant for the substantially faster writes. Those wanting stronger real-world performance at a similar price point should consider the Samsung 980 250GB, which trades a shorter warranty for better trace-based benchmark results. The NM620 256GB is a capable SATA replacement, nothing more and nothing less.

## Specifications

| Specification | Value |
| --- | --- |
| Capacity | 256 GB |
| Interface | M.2 3.0 x 4 |
| Controller | Lexar DM620 |
| Memory type | 3D TLC |
| DRAM cache | HMB |
| Sequential read | 3000 MB/s |
| Sequential write | 1300 MB/s |
| Random read IOPS | 300000 |
| Random write IOPS | 256000 |
| Endurance | 125 TBW |
| MTBF | 1.5 |
| Warranty | 5 years |

## Performance

The Lexar NM620 256GB is rated for up to 3,000 MB/s sequential reads and 1,300 MB/s sequential writes. Random performance comes in at up to 300,000 read IOPS and 256,000 write IOPS. Those sequential write numbers are roughly half of what the 1TB variant achieves — a direct consequence of fewer NAND dies sharing the write workload.

In practice, independent reviewers find the NM620 family delivers synthetic scores close to rated reads but falls short on sustained writes. The SLC cache on the 256GB model is relatively small; once it exhausts, write speeds settle to native TLC levels that can dip below 500 MB/s during large file transfers. For a boot drive handling mostly random reads and small writes, this limitation rarely surfaces. For anyone moving large video files or game libraries regularly, the 512GB or 1TB model is the better pick.

## Endurance, TBW & Warranty

Lexar rates the NM620 256GB at 125 TBW (Terabytes Written) over a five-year warranty period. That works out to approximately 68 GB of writes per day, every day, for five years — a figure that comfortably exceeds the typical desktop workload of 20 to 40 GB per day. The drive carries a 1.5 million hour MTBF rating, though this is a population-level statistical measure rather than a guarantee for any individual unit. The warranty is limited by whichever comes first: the five-year term or exceeding the TBW allowance.

## Pros and Cons

**Pros:**

- 3,000 MB/s sequential reads on PCIe 3.0
- Five-year warranty
- Single-sided M.2 2280 fits slim laptops
- DRAM-less HMB keeps cost down
- NVMe 1.4 support
**Cons:**

- 1,300 MB/s writes — less than half the 1TB model
- 125 TBW endurance is low for TLC
- No included heatsink or software toolbox
- Small SLC cache fills quickly on large transfers


## Verdict

The Lexar NM620 256GB is best suited as a low-cost boot or OS drive where the 1,300 MB/s write ceiling and 125 TBW endurance are unlikely to matter. Content creators and gamers who regularly move large files should step up to the 512GB or 1TB variant for the substantially faster writes. Those wanting stronger real-world performance at a similar price point should consider the Samsung 980 250GB, which trades a shorter warranty for better trace-based benchmark results. The NM620 256GB is a capable SATA replacement, nothing more and nothing less.

## Frequently Asked Questions

### Is the Lexar NM620 256GB good for gaming?

For game loading, yes — the NM620 256GB reads at 3,000 MB/s and handles random 4K reads well, which is what matters most for game load times. It will load games significantly faster than any SATA SSD. However, if you install a large game library on this drive, the limited 256GB capacity fills up fast, and write speeds during game installations or updates are capped at 1,300 MB/s.

### Does the Lexar NM620 256GB have DRAM cache?

No, the NM620 is a DRAM-less design. It uses the Host Memory Buffer (HMB) feature of the NVMe protocol to borrow a small amount of your system RAM for its flash translation layer. This keeps the drive affordable without a major performance penalty in everyday desktop use.

### What is the TBW endurance of the Lexar NM620 256GB?

The NM620 256GB is rated at 125 TBW (Terabytes Written), backed by a five-year warranty. At a typical consumer write workload of 20 to 40 GB per day, this drive would take between 8 and 17 years to exhaust its endurance rating — well beyond the warranty period.

### Is the Lexar NM620 256GB compatible with the PS5?

No, the PS5 requires a PCIe 4.0 NVMe SSD with a recommended sequential read speed of at least 5,500 MB/s. The NM620 256GB is a PCIe 3.0 drive with a maximum of 3,000 MB/s reads, which falls well below Sony's recommendation.

### How does the Lexar NM620 256GB compare to the Samsung 980 250GB?

Both are DRAM-less PCIe 3.0 NVMe drives in the entry-level segment. The Samsung 980 250GB generally performs better in real-world trace benchmarks like PCMark 10, while the NM620 256GB offers a longer warranty (five years versus three for the Samsung). The Samsung also has higher rated write speeds for the 250GB capacity. If warranty length matters most, the NM620 wins; for everyday performance, the Samsung edges ahead.

### Does the Lexar NM620 need a heatsink?

For typical desktop use as a boot drive, the NM620 256GB does not need an aftermarket heatsink. It generates relatively little heat under light workloads. However, during sustained benchmark runs or heavy write sessions, thermal throttling can occur on any bare M.2 SSD. If your motherboard has an M.2 heatsink built in, use it.

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Last updated: 2026-05-23. Source: https://ssdrive.net/lexar-nm620-256-gb