We have talked a lot about WD Black SN850 on SSD Sphere. We know it’s a very powerful SSD that can even beat the Samsung 980 Pro.
Today, there is another comparison with WD’s very popular SN770. So, without any delays, let’s get started.
Both of these drives are Gen 4 NVMe SSDs. But, the promised read/write speeds are really far from each other. So, if you are finding the best speed and are not worried about the price, you can go with the SN850 right here. The maximum theoretical speed of SN770 is 5150 MB/s while SN850 promises a whopping 7000 MB/s.
Another big difference is that SN850 has a DRAM cache while SN770 is a DRAM-Less NVMe drive. There are numerous other things to discuss these both. So, let’s start with the first one.
Theoretical Specifications
Specification | WD Black SN770 | WD Black SN850 |
---|---|---|
Storage Variants | 250GB, 500GB, 1TB, 2TB | 500GB, 1TB, 2TB |
Theoretical Read Speed (Max.) | 5,150 MB/s | 7,000 MB/s |
Theoretical Write Speed (Max.) | 4,850 MB/s | 5,300 MB/s |
Random Read (4K, QD32) (Max.) | Up to 7,40,000 IOPS | Up to 1,000,000 IOPS |
Random Write (4K, QD32) (Max.) | Up to 8,00,000 IOPS | Up to 1,000,000 IOPS |
Form Factor/Interface | M.2 (2280)/x4 PCIe 4.0/NVMe | M.2 (2280)/PCIe Gen 4.0 x 4/NVMe |
MTBF (Reliability) | 1.75 Million Hours | 1.75 Million Hours |
Warranty | 5 Years | 5 Years |
T.R.I.M. | Supported | Supported |
S.M.A.R.T. | Supported | Supported |
Encryption | No hardware encryption | No hardware encryption |
Heatsink Option | Not Available | Available |
Image | ![]() | ![]() |
Availability | Check Price | Check Price |
Besides the read/write speed numbers, there are no differences we can see at first look. Both of them are missing any kind of encryption. The same MTBF and warranty period are offered with both.
Synthetic Benchmark Scores Comparison
The test bench used for these benchmark tests has Intel Core i5 12600K CPU along with 4800MHz DDR5 (16GB) RAM. The motherboard is MSI Pro Z690-A. 1TB variants of both SSDs are used for these tests.
PassMark Scores Comparison

CrystalDiskMark Scores Comparison
CrystalDismMark is another simple-to-use storage benchmark software. It is generally used to run sequential and random system tests using different file sizes. The default sequential read/write test is 1M at Q8T1 and Q1T1. The default random read/write test is 4KB at Q32T1 and Q1T1. You can easily change these test types along with the total test file size.


3DMark Storage Benchmark
3DMark SSD Performance test for gamers is one of the best ways to check any SSD’s real-world gaming performance. A higher 3DMark’s Benchmark score means the SSD is good when it comes to game loading, progress saving, and installation as well. The tests are done with SN770’s Game mode enabled. When disabled, there is a slight reduction in the 3DMark Score.

PCMark 10- Trace Testing
Again, the game mode is disabled in PCMark 10 test.
PCMark 10 is one of the most popular benchmark software especially used by professionals. The quick system drive benchmark test is a smaller test utilizing smaller tests with softer real-world traces. This test is actually made for the drives which can’t handle the heavy load of Full System Drive Benchmark. The Full System Drive Benchmark, on the other hand, is full of heavy real-world traces from various popular applications. I have done both these tests and the comparison is as follows.

AS SSD Benchmark Scores
AS SSD is another very popular storage benchmarking software. It again runs some random tests to test sequential and random performance. You can set the test size from 1GB to 10GB. It will give you a score which can be helpful to compare the performance of two different SSDs.

Endurance
Parameter | WD Black SN770 | WD Black SN850 |
---|---|---|
TBW | 250GB: 200 500GB: 300 TBW 1TB: 600 TBW 2TB: 1,200 TBW | 500GB: 300 TBW 1TB: 600 TBW 2TB: 1,200 TBW |
Warranty | 5-Years Limited Warranty | 5-Years Limited Warranty |
MTBF (Mean Time Between Failure) | 1.75 Million Hours | 1.75 Million Hours |
All the endurance parameters are the same so there is nothing to talk about. 600 TBW for a 1TB drive is a good number for any high-end NVMe drive. However, the 5-years warranty period is what you will expect with any NVMe drive.
Technical Specifications
Technical Specification | WD Black SN770 | WD Black SN850 |
---|---|---|
NAND Flash Type | SanDisk’s TLC NAND | Sandisk’s TLC 3D |
NAND Flash Layers | 112 | – |
Controller | WD Proprietary | WD_BLACK G2 |
Controller Configurations | 4 Channel | Not Specified |
DRAM | No | DDR4 DRAM |
Heatsink Option | Not Available | Available |
T.R.I.M. | Available | Available |
S.M.A.R.T. | Available | Available |
Encryption | Not Available | Not Available |
Website | WD Black SN770 | WD Black SN850 |
Price
SN850 is a high-end NVMe and is expensive as compared to the SN770. But, the prices keep changing. So, you should always compare before buying.


Which one should you buy: SN770 or SN850?
By the time I am writing this article, WD Black SN850 1TB is around 30 bucks more expensive than the SN770 1TB. This price difference is huge if we look at the performance difference.
But, if you are looking for good performance under heavy read/write loads, WD Black SN850 is still worth this amount. It can go pretty well with powerful gaming or productivity builds.
However, if you are low on budget, SN770 will also make mostly everything possible for you. But, if your goal is to achieve consistent performance under huge loads, SN850 is the right pick for you.
Bonus:Other Gen 4 NVMe options
Kingston KC3000 | ![]() | 7000/7000 MB/s DDR4 DRAM TLC NAND 256-bit Encryption | Check Price |
Seagate Firecuda 530 | ![]() | 7300/6900 MB/s DDR4 DRAM TLC NAND 256-bit Encryption | Check Price |
Please let me know what you think about this article in the comments!