# Lexar NM990 4TB PCIe 5.0 NVMe SSD Review (2026)

The Lexar NM990 4TB tops the brand's budget PCIe 5.0 line, pairing a DRAM-less Maxio MAP1806A controller with Longsys TLC for 14,000 MB/s reads and 11,000 MB/s writes.

Quick answer: The Lexar NM990 4 TB is the top of the brand's budget PCIe 5.0 line, pairing the value Maxio MAP1806A plus Longsys TLC platform with maximum 4 TB capacity, the full 14,000 MB/s read speed, the family's best 11,000 MB/s write figure, a 2,400 TBW rating, a five-year warranty and an included heatsink. Its strengths are capacity, Gen5 read throughput and the highest write speed in the range, all at a budget price. Its weaknesses are the DRAM-less HMB design and the absence of prominent random IOPS figures. It suits a budget-conscious buyer who wants a large, fast Gen5 drive; most buyers are better served by the 2 TB sweet spot, and anyone who needs sustained random performance should look at a DRAM-equipped Gen5 drive like Lexar's own NM1090 Pro.

## Specifications

| Specification | Value |
| --- | --- |
| Capacity | 4 TB |
| Interface | M.2 5.0 |
| Controller | MaxioTech MAP1806A 8 Channel |
| Memory type | Longsys TLC |
| DRAM cache | HMB (no DRAM) |
| Sequential read | 14000 MB/s |
| Sequential write | 11000 MB/s |
| Random read IOPS |  |
| Random write IOPS |  |
| Endurance | 2400 TBW |
| MTBF | 2000000 |
| Warranty | 5 years |

## Performance

Lexar rates the NM990 4 TB at up to 14,000 MB/s sequential read and 11,000 MB/s sequential write, the highest write figure in the NM990 family. The read speed matches far more expensive Gen5 flagships, so for game loads, large file reads and DirectStorage-enabled asset streaming the drive feels genuinely fast, while the 11,000 MB/s write figure is the best in the range thanks to the most NAND die in parallel. Every NM990 capacity shares the 14,000 MB/s read rating, while write scales from 7,500 MB/s on the 1 TB up to 11,000 MB/s on the 4 TB, placing the flagship write speed on the largest capacity.

Because the NM990 is DRAM-less and relies on HMB, sustained random performance under heavy mixed workloads is lower than on DRAM-equipped drives, though for everyday desktop use and gaming the difference is rarely noticeable. The drive does not publish prominent random IOPS figures, which itself signals the value positioning. The Maxio MAP1806A is an 8-channel PCIe 5.0 controller, so the sequential throughput is real rather than aspirational, and the included heatsink helps it hold speed under load. For a 4 TB drive used for bulk fast storage plus a boot and game volume on a PCIe 5.0 platform, the NM990 delivers the family's best write speed alongside maximum capacity at a budget price.

## Endurance, TBW & Warranty

Lexar backs the NM990 with a five-year limited warranty, and the 4 TB model carries a 2,400 TBW (terabytes written) endurance rating, the highest in the lineup. That is strong coverage for a budget Gen5 drive: 2,400 TBW works out to roughly 1,315 GB of writes every single day for five years, staggeringly more than a typical 20 to 50 GB daily consumer workload. At 50 GB of writes per day you would need around 131 years to exhaust the rated endurance, so the NAND will outlast the warranty term many times over and wear is simply not a concern, even on a 4 TB drive holding a large media library. The five-year term is the binding limit, and it is generous for a value Gen5 drive where three-year cover is common. As an established brand Lexar offers a global support and RMA network, so keep your proof of purchase. The DRAM-less design means heavy sustained-write workloads are not this drive's strength, but endurance itself is not a realistic concern within the five-year window.

## Pros and Cons

**Pros:**

- Budget PCIe 5.0 with 14,000 MB/s reads
- 11,000 MB/s write, the highest in the NM990 family
- Maximum 4 TB capacity in a single M.2 slot
- Maxio MAP1806A 8-channel Gen5 controller
- Heatsink included
- 2,400 TBW endurance and 5-year warranty
**Cons:**

- DRAM-less HMB design limits sustained random performance
- Random IOPS figures not prominently published
- Needs a PCIe 5.0 platform to justify the read speed
- Highest price in the NM990 lineup


## Verdict

The Lexar NM990 4 TB is the top of the brand's budget PCIe 5.0 line, pairing the value Maxio MAP1806A plus Longsys TLC platform with maximum 4 TB capacity, the full 14,000 MB/s read speed, the family's best 11,000 MB/s write figure, a 2,400 TBW rating, a five-year warranty and an included heatsink. Its strengths are capacity, Gen5 read throughput and the highest write speed in the range, all at a budget price. Its weaknesses are the DRAM-less HMB design and the absence of prominent random IOPS figures. It suits a budget-conscious buyer who wants a large, fast Gen5 drive; most buyers are better served by the 2 TB sweet spot, and anyone who needs sustained random performance should look at a DRAM-equipped Gen5 drive like Lexar's own NM1090 Pro.

## Frequently Asked Questions

### Is the Lexar NM990 4TB good for gaming?

Yes. With 14,000 MB/s reads the NM990 4 TB handles fast game loads and DirectStorage-era titles with ease, and the 4 TB capacity holds an enormous game library alongside the operating system with room to spare. The 11,000 MB/s write is the best in the NM990 family and ample for gaming. It is a strong value pick for a budget Gen5 gaming build when you want maximum installed capacity, though the 2 TB offers better value for most players.

### Is the Lexar NM990 4TB compatible with the PS5?

Yes. The PS5 accepts standard M.2 2280 NVMe drives and PCIe 5.0 is backward compatible, but the PS5 expansion slot is PCIe 4.0, so the NM990 runs at Gen4 speeds rather than its full 14,000 MB/s. Conveniently the NM990 ships with a heatsink, which PS5 installation requires. At 4 TB it is an excellent PS5 upgrade for players who want a huge library always installed, though a cheaper native PCIe 4.0 drive offers similar PS5 performance for less.

### Does the Lexar NM990 have a DRAM cache?

No, the NM990 is a DRAM-less design that uses HMB (Host Memory Buffer), borrowing a small slice of system memory to manage the flash translation layer. This keeps cost and power draw low, which suits the drive's budget positioning, but it means sustained random performance under heavy mixed workloads is lower than on drives with a dedicated DRAM cache. For everyday and gaming use, which are read-heavy, the difference is rarely noticeable.

### What is the TBW endurance of the Lexar NM990 4TB?

The 4 TB NM990 is rated at 2,400 TBW (terabytes written) over its life, the highest in the lineup, backed by a five-year warranty. That is roughly 1,315 GB of writes per day for five years, far beyond any normal 20 to 50 GB daily workload, so the NAND outlasts the warranty by more than a century in typical use. Endurance is not a concern even on a drive this large.

### How does the Lexar NM990 4TB compare to the 1TB and 2TB models?

All three capacities share the same Maxio MAP1806A controller, Longsys TLC NAND, 14,000 MB/s read speed and five-year warranty, but write speed scales with capacity: the 1 TB writes at 7,500 MB/s, the 2 TB at 10,000 MB/s and the 4 TB at 11,000 MB/s, the family's best. The 4 TB also carries the highest 2,400 TBW endurance. The 2 TB remains the value sweet spot; the 4 TB is for buyers who want maximum capacity plus the NM990's best write speed.

### How does the Lexar NM990 compare to the Lexar NM1090 Pro?

Both are Lexar PCIe 5.0 drives but they target different buyers. The NM1090 Pro is the flagship with a Silicon Motion SM2508 controller, Micron TLC, a DRAM cache, higher IOPS and higher write speeds. The NM990 is the value DRAM-less option using Maxio's MAP1806A and Longsys TLC, with 14,000 MB/s reads but lower writes and no DRAM. Choose the NM1090 Pro for peak Gen5 performance; choose the NM990 for Gen5 read speed and capacity at the lowest price.

### Does the Lexar NM990 4TB need a heatsink?

It already includes one. The NM990 ships with a heatsink fitted, which is a thoughtful inclusion for a budget Gen5 drive given how hot PCIe 5.0 parts run under sustained writes. That makes it convenient for PS5 installation and for desktop boards that lack a dedicated M.2 heatsink. You do not need to buy a separate heatsink for this drive.

---

Last updated: 2026-06-29. Source: https://ssdrive.net/lexar-nm990-4-tb