Jesper Berg 
In the second half of 2023, Samsung has yet to launch a PCI-Express (PCIe) Gen5 M.2 drive in the consumer market. This means that the Gen4 990 PRO is still Samsung’s flagship – and also one of (if not the) fastest SSDs for the PCI-Express 4.0 interface.
Western Digital is also biding its time with Gen5, meaning that the SN850X is the performance leader in the WD Black lineup. The WD Black SN770 is a more affordable alternative in the series and ships without onboard DRAM.
In other words, the midrange SN770 is not a direct competitor of the 990 PRO but is known to offer excellent performance in spite of its DRAM-less design.
SN770 Vs. 990 PRO: Specifications
Specifications for the full 990 PRO and SN770 series can be found further down on this page. This table compares the 2TB capacities of each drive.
Last update on 2024-04-26 / Affiliate links / Images from Amazon Product Advertising API
Unsurprisingly, the Samsung flagship is ahead of the SN770 by substantial marigins in all performance-related areas. It uses nearly all of the bandwidth that the PCIe 4.0 x4 interface has to offer and is almost 45% faster than the WD Black SN770 in terms of sequential read performance. The 990 PRO is even further ahead of the SN770 as measured in random IOPS. In fact, the only matching part of the spec sheets are warranty terms and endurance.
Both drives use a custom combination of a proprietary controller and NAND memory chips, but a potentially more important difference is that the Samsung 990 PRO is assisted by a DDR4 buffer integrated on the tiny M.2 PCB.
SN770 Vs. 990 PRO: Performance
On the other hand, theoretical maximums as seen on the spec sheets are not the same thing as performance in real-world scenarios. The SN770 is widely seen as one of the best DRAM-less M.2 SSDs, but is it fast enough to close in on the 990 PRO? Here’s how they differ according to our reviews of the 2TB WD Black SN770 and 2TB Samsung 990 PRO.
AS SSD Sequential Performance
No SSD will reach its theoretical maximum sequential performance in the AS SSD benchmark, but it still largely reflects the same differences in this case. The 990 PRO’s read speed is 35% higher than the SN770 and write speed is about 37% better.
CrystalDiskMark Sequential & Random Performance
Sequential performance according to CrystalDiskMark follows the same pattern, with the Samsung 990 Pro being about 35–40% ahead of the WD Black SN770.
On the other hand, the most common workload for the average office or gaming PC is not orderly transfers of large files. That’s why performance with small chunks of random data is usually a better proxy for everyday performance. The Samsung flagship is nevertheless substantially ahead of the SN770 here.
Latency (Anvil’s Storage Utilities)
Latency or response time is another important metric for a number of everyday workloads. Samsung’s Gen4 flagship is about 32% (read) and 24% (write) faster than the WD Black SN770 in this area.
SN770 Vs. 990 PRO: Real-World Performance
UL’s PCMark 10 benchmark includes a test of actual startup times for common office apps. Here, the differences are much less pronounced and the Samsung SSD is even marginally slower than the SN770 in a single outlier.
When the standalone Final Fantasy Shadowbringer benchmark combines the loading times for five different game levels, the Samsung drive’s total is 1.6 seconds or 18.8% lower than the WD Black SSD.
3DMark Storage Benchmark
The 3DMark Storage Benchmark is a more diverse combination of gaming workloads that includes installing, copying, loading, and recording games. As measured in average bandwidth, the 990 PRO is 40.7% faster than the SN770.
PlayStation 5 Read Speed Test
The WD Black SN770 is not compliant with Sony’s recommendations but will still work as a PS5 storage expansion SSD. The Samsung 990 PRO is better suited for this task (preferably in combination with a heatsink as per Sony’s recommendations) and also faster.
Conclusion
Overall Winner: Samsung 990 PRO
On average, Samsung’s 990 PRO is substantially faster than the Western Digital WD Black SN770 in synthetic benchmarks and also in tests that reflect real-world scenarios. However, it is also more expensive than the SN770, which remains a solid budget M.2 SSD.
read more:
- Full review of the 2TB 990 PRO
- Full review of the 2TB WD_Black SN770
- Comparison of the WD_Black SN850X Vs. SN770
- Comparison of the WD_Black SN850X Vs. 990 PRO
- Ranking of the best M.2 SSDs
- Ranking of the fastest SSDs overall (incl. SATA)
- Best budget M.2 NVMe SSDs
Samsung 990 PRO Series Specifications
| Samsung 990 PRO Specifications | 1TB | 2TB | 4TB |
|---|---|---|---|
| Form Factor | M.2 2280 | M.2 2280 | M.2 2280 |
| Interface/ Protocol | PCIe 4.0 x4/ NVMe 2.0 | PCIe 4.0 x4/ NVMe 2.0 | PCIe 4.0 x4/ NVMe 2.0 |
| Controller | Pascal | Pascal | Pascal |
| DRAM | 1GB LPDDR4 | 2GB LPDDR4 | 4GB LPDDR4 |
| Memory | 176-layer 3D TLC | 176-layer 3D TLC | 176-layer 3D TLC |
| Sequential Read | 7,450 MB/s | 7,450 MB/s | 7,450 MB/s |
| Sequential Write | 6,900 MB/s | 6,900 MB/s | 6,900 MB/s |
| Random Read | 1.2M IOPS | 1.4M IOPS | 1.4M IOPS |
| Random Write | 1.55M IOPS | 1.55M IOPS | 1.55M IOPS |
| Endurance | 600 TBW | 1,200 TBW | 2,400 TBW |
| Warranty | 5-Year | 5-Year | 5-Year |
WD Black SN770 Series Specifications
| WD Black SN770 | 250GB | 500GB | 1TB | 2TB |
|---|---|---|---|---|
| Form Factor | M.2 2280 | M.2 2280 | M.2 2280 | M.2 2280 |
| Interface / Protocol | PCIe 4.0 x4 / NVMe 1.4 | PCIe 4.0 x4 / NVMe 1.4 | PCIe 4.0 x4 / NVMe 1.4 | PCIe 4.0 x4 / NVMe 1.4 |
| Controller | Proprietary | Proprietary | Proprietary | Proprietary |
| DRAM | No | No | No | No |
| Memory | 112-Layer TLC | 112-Layer TLC | 112-Layer TLC | 112-Layer TLC |
| Sequential Read | 4,000 MB/s | 5,000 MB/s | 5,150 MB/s | 5,150 MB/s |
| Sequential Write | 2,000 MB/s | 4,000 MB/s | 4,900 MB/s | 4,850 MB/s |
| Random Read | 240K IOPS | 460K IOPS | 740K IOPS | 650K IOPS |
| Random Write | 470K IOPS | 800K IOPS | 800K IOPS | 800K IOPS |
| Endurance | 200 TBW | 300 TBW | 600 TBW | 1,200 TBW |
| Warranty | 5-Years | 5-Years | 5-Years | 5-Years |
| MSRP | $59.00 | $79.00 | $129.00 | $269.00 |
