For PCIe Gen4 NVMe, the Samsung 990 Pro and WD Black SN850X are the two drives that keep coming up in every serious PC builder's research. Both are fast. Both are reliable. The differences are real but subtle — and which one wins depends heavily on what you're doing with it.
Samsung 990 Pro 2TB
The WD Black SN850X is the better gaming drive. Its Game Mode 2.0 firmware and slightly faster sustained read speeds give it an edge for PS5 and gaming PC use. The 990 Pro is the better all-around workstation drive, with better write consistency and lower thermals under sustained workloads.
Specs Comparison
| Spec | Samsung 990 Pro 2TB | WD Black SN850X 2TB |
|---|---|---|
| Interface | PCIe 4.0 x4 NVMe 2.0 | PCIe 4.0 x4 NVMe 1.4 |
| Sequential Read | 7450 MB/s | 7450 MB/s |
| Sequential Write | 6900 MB/s | 6900 MB/s |
| Random Read IOPS | 1.4M | 1.3M |
| Endurance (2TB) | 1200 TBW | 1200 TBW |
| Warranty | 5 years | 5 years |
| Thermals | Better | Higher under sustained load |
| Approx. Price (2TB) | ~$130 | ~$120 |
Sequential Speed
Both drives are rated for 7450 MB/s sequential read. In AnandTech's testing, the SN850X hit about 7440 MB/s reads and the 990 Pro landed at 7410 MB/s — effectively identical. Sequential writes are where they diverge: the SN850X claims 6900 MB/s to the 990 Pro's 6900 MB/s, again a wash.
Random IOPS tell a more interesting story. Tom's Hardware measured the 990 Pro at around 1.4 million 4K random read IOPS and about 1.55 million random write IOPS under steady-state conditions. The SN850X comes in near the same numbers but shows slightly more variance under mixed workloads.
Gaming Performance
WD's Game Mode 2.0 firmware adjusts power states and prioritizes read requests in patterns that match game engines. In Tom's Hardware's game load tests, the SN850X shaved fractions of a second off load times in DirectStorage-enabled titles. Not transformative, but consistently ahead.
For PS5 use, the SN850X was one of the first recommended upgrades — its compatibility is rock solid. The 990 Pro works well in the PS5 too, but WD's heatsink options are better suited to the PS5's thermal constraints.
Thermals and Sustained Performance
The 990 Pro runs cooler. Samsung's newer controller design dissipates heat more efficiently, and in extended sequential write tests it maintains closer to rated speed without throttling. The SN850X tends to thermal-throttle faster on long sequential writes without a heatsink.
For a NAS or always-on workstation environment, the 990 Pro's thermal behavior makes it the better long-term choice.
Price and Value
At 2TB, both drives typically land within $10–$20 of each other. The SN850X goes on sale more frequently through WD's own store. The 990 Pro holds its price steadier but comes up in Amazon sales.
Both drives carry five-year warranties and 1200 TBW endurance ratings at 2TB — class-standard specs.
Samsung 990 Pro 2TB Strengths
- Better sustained write performance under heavy workloads
- Cooler thermals, less throttling on long writes
- Excellent Samsung Magician software
- Strong consistency in AnandTech benchmarks
WD Black SN850X 2TB Strengths
- Game Mode 2.0 for DirectStorage titles
- Strong PS5 upgrade compatibility
- Better heatsink options for PS5 form factor
- Slightly faster in gaming load benchmarks
Samsung 990 Pro 2TB Weaknesses
- Slightly higher price at 2TB in most markets
- Samsung Magician requires Windows for full features
- No firmware 'gaming mode' optimization
WD Black SN850X 2TB Weaknesses
- Thermal throttling faster on extended sequential writes without heatsink
- WD Dashboard software is less polished than Samsung Magician
- Slightly higher power consumption
Best For
- a: Workstation builds, video editing, content creation, sustained read/write workflows
- b: Gaming PCs and PS5 upgrades where load time optimization matters
FAQ
Does either drive need a heatsink?
If your motherboard doesn't have an M.2 heatsink, add one. Both drives benefit, but the SN850X benefits more. Most modern boards include one.
Is PCIe Gen 5 worth waiting for?
Gen 5 drives are available but remain expensive and run very hot without beefy heatsinks. Gen 4 drives like these two are the sweet spot for price-to-performance through 2026.
Are these compatible with the PS5?
Yes, both are compatible. The SN850X has a slight edge in PS5-specific testing, and WD sells a PS5-specific heatsink bundle.