In 2022, there were numerous new releases in the Gen 4 NVMe market. But, two of the most discussed ones are WD Black SN850X and Samsung 990 Pro. So, which one should you go for in 2023?
WD Black SN850X is called the updated version of the older SN850. However, the 990 Pro is the successor to the 980 Pro.
Both of these are equipped with the TLC NAND Flash.
There are various other similarities but some differences between the both. So, if you are confused and want to choose one of these, I am here to help you. Let’s start our comparison right away.

Theoretical Specifications
Specification | WD Black SN850X | Samsung 990 Pro |
---|---|---|
Storage Variants | 1TB, 2TB, 4TB | 1TB, 2TB, 4TB |
Theoretical Read Speed (Seq) | Up to 7,300 MB/s | Up to 7,450 MB/s |
Theoretical Write Speed (Seq) | Up to 6,300 MB/s | Up to 6,900 MB/s |
Random Read Speed | Up to 1,200K IOPS | Up to 1,400K IOPS |
Random Write Speed | Up to 1,100K IOPS | Up to 1,550K IOPS |
Warranty | 5 Years | 5 Years |
Heatsink Option | Available | Available |
Encryption | Not Available | Available |
Price | Check Amazon | Check Amazon |
The theoretical sequential read speed of the Samsung 990 Pro is up to 7,450 MB/s, which is 150 MB/s faster than the WD Black SN850X’s sequential read speed of up to 7,300 MB/s. Similarly, the Samsung 990 Pro’s theoretical sequential write speed is up to 6,900 MB/s, which is 600 MB/s faster than the WD Black SN850X’s sequential write speed of up to 6,300 MB/s.
The Samsung 990 Pro has 200K IOPS higher random speed i.e. 1,400K IOPS, while the WD Black SN850X has a random read speed of up to 1,200K IOPS. In terms of random write speed, the Samsung 990 Pro has a speed of up to 1,550K IOPS, which is 450K IOPS faster than the WD Black SN850X’s speed of up to 1,100K IOPS.
The main drawback of the SN850X is that it comes with no encryption.
Benchmark Scores Comparison
The Test-Bench Specifications are:
CPU: Intel Core i5 12600K
RAM: DDR5 4800 MHz (8x2GB)
Motherboard: MSI Pro Z690-A
OS: Windows 11 Pro
All the tests are done on the 2TB variants of both drives. They are 0% filled during the benchmark tests.
Sequential Read/Write Performance

There is a very minimal difference in the sequential read/write performance of both these drives. However, the Samsung 990 Pro is winning the game by small numbers.
Random Read/Write Performance (IOPS)

Again, the Samsung 990 Pro is winning the game in random read performance. But, the random write performance is better with the KC3000.
3DMark SSD Test for Gamers
This test specifically tests the drives for their performance in-game loading, game saving, and overall gaming performance.

Both the SSDs come with dedicated game modes which don’t seem to have any major impact on the gaming performance at all. However, the overall performance is almost similar with both SSDs.
PCMark 10 Full System Drive Benchmark
In the PCMark 10 Full System Drive benchmark, the software writes 204 GB data over a period of time. This test covers different types of tasks including Adobe applications, MS Office, File Transfer, etc. Also, the startup time of some games including Battlefield V, Overwatch, and Battlefield are calculated.

Anvil’s Storage Benchmark

AS SSD Benchmark Scores

The results are clear. Samsung 990 Pro is the winner in terms of gaming, productivity, sequential read/write, and random read/write performance. In other words, it will be capable of offering you a better performance in the real-world than the SN850X.
But, keep in mind that the SN850X is also a pretty powerful SSD than other competitors. So, you should not take it off your list. Its cheaper price can make a big difference for some buyers.
Endurance and TBW
Parameter | WD Black SN850X | Samsung 990 Pro |
---|---|---|
TBW | 1TB: 600 TBW 2TB: 1,200 TBW 4TB: 2,400 TBW | 1TB: 600 TBW 2TB: 1,200 TBW |
Warranty | 5-Years Limited Warranty | 5-Years Limited Warranty |
MTBF (Mean Time Between Failure) | 1.80 Million Hours | 1.50 Million Hours |
There are no differences in both when it comes to endurance (TBW). But, the MTBF is higher in the SN850X. So, theoretically, it can last longer than the 990 Pro.
Technical Specificiations
Technical Specification | WD Black SN850X | Samsung 990 Pro |
---|---|---|
NAND Flash Type | Sandisk’s TLC | Samsung’s TLC |
NAND Flash Layers | 112 | 176 |
Controller | WD Proprietary | Samsung Pablo Controller |
Controller Configurations | Tri-Core, 4-Channels | Not Specified |
DRAM | DDR4 DRAM | DDR4 SDRAM |
Heatsink Option | Available | Available |
T.R.I.M. | Available | Available |
S.M.A.R.T. | Available | Available |
Encryption | Not Available | Available |
Details | Datasheet | Datasheet |
Price


Which one to buy? WD Black SN850X or Samsung 990 Pro
By the time I am writing this article, the Samsung 990 Pro is around 30$ more expensive than the SN850X. So, if you want to save some money on this purchase without compromising a lot on the performance, I would recommend going for the SN850X.
On the other hand, if you are looking for the best performance possible, Samsung 990 Pro is made for you. It also has the feature of encryption with a better controller. The write cache is better with the 990 Pro. So, clearly, Samsung 990 Pro is the winner of this game.
Let me know your thoughts in the comments!
Other Gen4 SSDs to look at
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 |