⚡Quick Answer+

The Lexar NM790 offers better value with faster specs (7,400 vs 5,150 MB/s) at lower prices. The WD SN770 appeals to buyers who prefer brand recognition. Both are DRAM-less and work well for gaming. For PS5, the NM790 is the budget community favorite. Real-world gaming difference is 0.5-1.5 seconds — both are "fast enough."

Key Takeaways:

NM790: 44% faster specs, usually cheaper
SN770: WD brand recognition, proven reliability
Both: DRAM-less, fine for gaming
PS5: NM790 is the value pick

The WD Black SN770 and Lexar NM790 represent two philosophies in the budget Gen 4 SSD market. WD brings mainstream brand recognition, conservative specs, and proven reliability. Lexar counters with aggressive specifications (7,400 MB/s vs 5,150 MB/s) and even lower pricing — often 15-25% less than the SN770.

Both drives are DRAM-less, using Host Memory Buffer (HMB) technology instead. This is the key cost-saving measure that makes sub-$100 Gen 4 drives possible. For gaming and typical desktop use, DRAM-less designs work perfectly fine. For heavy professional workloads, flagship drives with DRAM are still preferable.

This comparison cuts through the specs to answer the real question: should you trust the established WD brand or take a chance on Lexar's impressive specifications at an even lower price?

SN770 vs NM790: Full Specs Comparison

Specification	WD Black SN770	Lexar NM790
Interface	PCIe Gen 4 x4	PCIe Gen 4 x4
Capacities	250GB, 500GB, 1TB, 2TB	512GB, 1TB, 2TB, 4TB
Sequential Read	5,150 MB/s	7,400 MB/s
Sequential Write	4,900 MB/s	6,500 MB/s
Random Read (IOPS)	740K	1,000K
Random Write (IOPS)	800K	900K
Controller	WD/SanDisk Custom	Maxio MAP1602
NAND	Kioxia BiCS5 112-Layer TLC	Longsys/YMTC 232-Layer TLC
DRAM Cache	No (HMB)	No (HMB)
Endurance (1TB)	600 TBW	800 TBW
Warranty	5 years	5 years
Heatsink Included	No	No
PS5 Compatible	Yes ✓ (with heatsink)	Yes ✓ (with heatsink)
Typical Price (1TB)	~$70-80	~$55-65

Key Differences Explained

Sequential Speed

The NM790 is 44% faster on paper: 7,400 vs 5,150 MB/s reads. This is a massive spec difference. In real-world gaming, however, the gap narrows significantly — we're talking 1-2 seconds in most scenarios.

Advantage: Lexar (significant on paper)

Price

The NM790 typically costs $10-20 less than the SN770 at each capacity. Combined with faster specs, Lexar's value proposition is compelling — if you trust the brand.

Advantage: Lexar (significant)

Brand & Track Record

WD/SanDisk is a household name with decades of storage history. Lexar (owned by Longsys) is less familiar to Western consumers despite quality products. Some buyers prefer the peace of mind.

Advantage: WD

Capacity Options

Lexar offers up to 4TB; WD caps at 2TB. If you want maximum capacity in a budget DRAM-less drive, the NM790 is your only choice between these two.

Advantage: Lexar

Controller Quality

WD uses their own custom controller; Lexar uses Maxio MAP1602. Both are proven in budget drives. WD's vertical integration provides tighter optimization.

Advantage: WD (marginal)

Endurance

The NM790 is rated higher: 800 TBW vs 600 TBW at 1TB. Both exceed what typical users will ever write. Lexar's higher rating reflects confidence in their 232-layer NAND.

Advantage: Lexar

Real-World Performance: Gaming, PS5 & Daily Use

The spec gap is misleading. On paper, the NM790's 7,400 MB/s should demolish the SN770's 5,150 MB/s. In practice, real-world gaming performance is much closer than specs suggest. Here's why:

Gaming (PC): Modern games don't sustain maximum sequential reads. They load in bursts with lots of small random reads. In game load time tests, the NM790 is typically 0.5-1.5 seconds faster — noticeable but not dramatic. Both drives feel fast and responsive. The SN770's lower specs are still 5-10x faster than any HDD.

PS5 Gaming: The NM790's 7,400 MB/s gives it more headroom above Sony's 5,500 MB/s requirement, but both drives deliver identical PS5 game load times. Sony's I/O controller standardizes performance. The SN770 barely meets the spec but works perfectly. Both require aftermarket heatsinks (~$10).

Boot Times & App Launching: Virtually identical. Windows boot, app launches, and general system responsiveness feel the same on both drives. The speed difference only appears in sustained sequential transfers.

Large File Transfers: Here the NM790 shines. Copying large video files, game folders, or backups shows a meaningful 20-30% speed advantage. If you frequently move large files, the NM790's faster sequential speeds provide real benefit.

Understanding DRAM-less SSDs

Both the SN770 and NM790 lack dedicated DRAM cache, instead using Host Memory Buffer (HMB) technology that borrows a small portion of your system RAM. This is how they achieve low prices while maintaining decent performance.

When DRAM-less is fine:

Gaming: Games load sequentially; HMB handles this well
Boot drive: OS loads are largely sequential; no issue
General desktop use: Web browsing, Office, media — perfect
Secondary storage: Game libraries, media, backups

When DRAM matters more:

Database workloads: Lots of random small reads/writes
Virtual machines: Heavy random I/O patterns
Professional video editing: Scratch disks with constant access
Heavy multitasking: Many apps accessing storage simultaneously

For 90% of users — gamers, students, home office, general computing — DRAM-less drives like the SN770 and NM790 perform excellently. Don't let "no DRAM" scare you away from great value.

Brand Trust: WD vs Lexar

Western Digital needs no introduction. Along with Seagate, they've dominated storage for decades. WD acquired SanDisk in 2016, combining two storage giants. The SN770 carries the "WD Black" gaming brand — their premium consumer line. Support, warranty claims, and availability are excellent.

Lexar has a more complex history. Originally a Micron brand, it was sold to Longsys (a major Chinese flash manufacturer) in 2017. Under Longsys ownership, Lexar has released competitive products using their parent company's manufacturing capabilities. The NM790 has earned excellent reviews and strong community reception, particularly among PS5 users seeking value.

Should you trust Lexar? Yes. Longsys is a legitimate flash manufacturer, not a fly-by-night brand. Lexar offers the same 5-year warranty as WD. Amazon reviews are positive, and tech communities (Reddit's r/buildapc, r/PS5) frequently recommend the NM790. The "unknown brand" stigma is outdated.

That said, some buyers simply feel more comfortable with WD's name recognition. That peace of mind has value — just know that Lexar is genuinely reliable, not just cheap.

WD Black SN770 — Current Prices

All SN770 options sorted by price per TB. Updated hourly from Amazon.

Product	Capacity	Price	$ / TB	Price Drop	Brand	Interface

Lexar NM790 — Current Prices

All NM790 options sorted by price per TB. Updated hourly from Amazon.

Product	Capacity	Price	$ / TB	Price Drop	Brand	Interface

Frequently Asked Questions: SN770 vs NM790

Is the Lexar NM790 really 44% faster than the WD SN770?

In sequential benchmarks, yes. The NM790 hits 7,400 MB/s vs the SN770's 5,150 MB/s. However, real-world gaming performance is much closer — typically 0.5-1.5 seconds difference in game loads. The dramatic spec gap only manifests in large sustained file transfers. For everyday use and gaming, both drives feel similarly fast.

Which is better for PS5: SN770 or NM790?

The NM790 is the better PS5 value. Both work, but the NM790 offers more headroom above Sony's 5,500 MB/s requirement (7,400 vs 5,150 MB/s) at a lower price. The SN770 meets the spec but barely. Real-world PS5 load times are identical, but the NM790's better value and higher spec margin make it the preferred choice. Both need aftermarket heatsinks (~$10).

Is Lexar a reliable brand?

Yes, Lexar is reliable. Owned by Longsys, a major Chinese flash manufacturer with vertical integration (they make their own NAND). The NM790 has excellent reviews and strong community recommendations. Lexar offers the same 5-year warranty as WD. While less familiar than WD in Western markets, Lexar products are genuinely trustworthy.

Does "no DRAM" matter for gaming?

No, DRAM-less is fine for gaming. Both drives use Host Memory Buffer (HMB) which works excellently for gaming's sequential load patterns. Games load assets in predictable ways that HMB handles well. You'd only notice DRAM benefits in database-heavy workloads, virtual machines, or extremely heavy multitasking. For 90% of users, DRAM-less drives like these perform great.

Should I just buy a Samsung 990 EVO instead?

The 990 EVO costs more but offers DRAM. If budget allows, the Samsung 990 EVO (~$100-110 for 1TB) provides flagship-adjacent performance with DRAM cache and Samsung's vertical integration. But if you're budget-focused, the NM790 and SN770 deliver 90% of the experience at 60-70% of the price. For pure gaming, DRAM matters less than you'd think.

Which has better warranty support?

Both offer 5-year warranties. WD has more retail presence and established customer service infrastructure in Western markets. Lexar warranty claims go through their support portal. Both honor warranties properly. WD's brand recognition may make the claims process feel more familiar, but Lexar support is responsive. For most users who never need warranty service, it's a non-issue.

Why is the SN770 so slow compared to other Gen 4 drives?

WD prioritized value over specs. The SN770 launched in 2022 as a budget Gen 4 option with conservative specifications. WD optimized for efficiency, low power consumption, and reliability rather than benchmark numbers. It's technically Gen 4 but performs closer to high-end Gen 3. This isn't a flaw — it's a design choice that keeps prices low while still being "fast enough" for gaming.

Final verdict: Which should I buy?

The Lexar NM790 offers better value for most users. It's faster on paper, typically cheaper, and has proven reliable. Choose the WD SN770 if: brand recognition gives you peace of mind, you found it on sale cheaper than the NM790, or you prefer WD's ecosystem. For PS5 expansion specifically, the NM790 is the budget community's top recommendation. Check current prices above — the better deal wins.