The read speed is increased to 7,300MB/s, and the write increase can reach 6,600MB/s and 1,100,000 IOPS.
Western Digital announced the WD_BLACK SN850X in May, and will replace the WD_BLACK SN850 as the new representative of the PCIe 4.0 NVMe high-end product line. Recently, the WD_BLACK SN850X has been launched in Taiwan one after another. Let’s take a look at the difference.
The WD_BLACK SN850X is based on the WD_BLACK SN850 and enhanced. On the basis of the same PCIe 4.0 x4 NVMe interface, Western Digital further pushes the access speed to the extreme. Especially the write performance, the WD_BLACK SN850X can reach at least 6,300MB/s and 1,100,000IOPS. Compared with the WD_BLACK SN850 with a maximum of 5,300MB/s and 720,000IOPS, the WD_BLACK SN850X squeezes into the new generation of PCI 4.0 NVMe high-performance forest.
Western Digital has also brought some changes. This generation of the heatsink-equipped version adds RGB lighting effects to meet the WD_BLACK target consumer group, which is the preference of gamers. As for the Western Digital SSD Dashboard tool software, the Game Mode acceleration function has been upgraded to version 2.0, and the game startup detection mechanism has been improved, claiming that it can more effectively shorten the loading time and reduce the delay.
WD_BLACK SN850X product line composition
WD_BLACK SN850X provides 1, 2, and 4TB capacity options. Compared with WD_BLACK SN850, it cancels 500GB but adds a 4TB capacity version. The market reference price I found is as follows, which is roughly several hundred yuan more than WD_BLACK SN850. It is equipped with a heat sink version, and the mechanism design is still compatible with the PlayStation 5 game console, but the 4TB capacity version option is not currently available.
| market reference price | WD_BLACK SN850X | WD_BLACK SN850 |
|---|---|---|
| 1TB | $4,500 | – |
| 1TB with heatsink | $5,400 | $5,300 |
| 2TB | $7,450 | $6,500 |
| 2TB with heatsink | $8,150 | $6,990 |
| 4TB | $22,430 | x |
Western Digital provides samples of the 2TB capacity version without heatsinks. The actual appearance is almost the same as that of the WD_BLACK SN850, which is different from the schematic diagrams on the official website. On the basis of the same M.2 Type 2280 printed circuit board, the core key components have changed. The SanDisk model 20-82-20035-B2 controller seems to be a small revision of the one used by the WD_BLACK SN850. Designed for PCIe 4.0 x4 / NVMe 1.4 interface, 8 lanes.
The biggest difference of the WD_BLACK SN850X is the use of BiCS5 flash memory. This generation of TLC 3D NAND is designed for 112-layer stacking. In contrast, the WD_BLACK SN850 was launched with 96-layer BiCS4 products. BiCS 5 has improved capacity density and access performance. . The 2TB capacity version can be seen from the side, with 2 flash memory, 1 dynamic random access memory plus a controller, 4 chips are all concentrated on one side of the circuit board, and it is not difficult to fit into a laptop heat dissipation.
These two changes have a very direct impact on performance. Basically, most of the WD_BLACK SN850X have been improved. You can refer to the following performance specifications. The special case is the 1TB capacity version. The random read of WD_BLACK SN850X is only 800,000 IOPS, which is a bit lower than that of WD_BLACK SN850 of 1,000,000 IOPS. It is probably related to factors such as the particle/capacity composition relationship.
The write performance has been relatively improved. The sequential write capacity of the 1TB version is 6,300MB/s, and the rest can reach 6,600MB/s. On the other hand, the WD_BLACK SN850 is only 5,300MB/s in the best 1TB version, and the improvement is at most 5,300MB/s 29.4%. While random write it is uniform at 1,100,000IOPS, WD_BLACK SN850 is best at 720,000IOPS, so the difference is up to 54.9%.
| WD_BLACK SN850X | WD_BLACK SN850 | |||||
|---|---|---|---|---|---|---|
| 1TB | 2TB | 4TB | 500GB | 1TB | 2TB | |
| Sequential read (MB/s) | 7,300 | 7,300 | 7,300 | 7,000 | 7,000 | 7,000 |
| Sequential Write (MB/s) | 6,300 | 6,600 | 6,600 | 4,100 | 5,300 | 5,100 |
| Random Reads (IOPS) | 800,000 | 1,200,000 | 1,200,000 | 810,000 | 1,000,000 | 1,000,000 |
| Random Writes (IOPS) | 1,100,000 | 1,100,000 | 1,100,000 | 680,000 | 720,000 | 710,000 |
| Endurance/Writability (TBW) | 600 | 1,200 | 2,400 | 300 | 600 | 1,200 |
| Operating temperature (°C) | 0～85 | 0～85 | 0～85 | 0～70 | 0～70 | 0～70 |
The remaining specifications such as endurance/write (TBW) remain at the same level, under the condition of 5-year limited warranty service, the 1TB capacity version is still 600TBW and the rest doubles accordingly. It is interesting that the upper limit of operating temperature is relaxed from 70°C to 85°C. The official emphasizes that the heat management mechanism has been updated, and the change in performance due to the increase in temperature is relatively gentle, especially when it exceeds 55°C, the speed will be much higher than WD_BLACK. SN850.
WD_BLACK SN850X performance test experience
The additional software Western Digital SSD Dashboard, the main functions and interface have not changed, so the repeated items will not be repeated. The exclusive acceleration function Game Mode 2.0 of the WD_BLACK series will enter the enhanced mode when the game is detected to start, which can reduce the loading speed and delay. If the misjudgment fails, you can also specify the game directory in the settings. The results of the simple test are attached below.
The performance test experience starts from the AIDA64 writing test. The initial speed of WD_BLACK SN850X can reach about 5,600MB/s, which is not much higher than that of WD_BLACK SN850. Its cache action range is also close to 34%. After saturation, it drops to 1,460-5,100MB/s, and the middle value is about 2,900MB/s, which is higher than the WD_BLACK SN850X. The result is also reflected in the average speed.
testing platform
During the AIDA64 writing test, the maximum temperature was 62°C with the help of tool software. This is the result with the heatsink of the motherboard and the air flow conditions. Western Digital’s thermal management mechanism, in vernacular terms, is that the overheating speed reduction protection point is relaxed and delayed. Although it claims that the speed will be much higher than that of the WD_BLACK SN850 at high temperature, the heat dissipation treatment during the installation process is still sloppy.
In the benchmark test, Seagate FireCuda 530 SSD 2TB is selected as the main representative group (sequential read 7,300MB/s, write 6,900MB/s, random read and write 1,000,000IOPS). Tuning is one of the best. As for the WD_BLACK SN850, it should be noted that the test archive data is a 1TB capacity version, so it is not suitable to be used to fight against each other.
In the ATTO Disk Benchmark test, before the random read of WD_BLACK SN850X reaches the depth of QD 32, the throughput and stability are not as good as FireCuda 530 SSD, but it can advance since QD 32, and the rest of the projects are mostly slightly better. This tendency can also be observed in Anvil’s Storage Utilities, FireCuda 530 SSD usually performs slightly better before QD 32, and then WD_BLACK SN850X starts to fight back.
Therefore, in terms of IOPS, CrystalDiskMark shows that the FireCuda 530 SSD is in the lead under the QD1T1 condition, while the WD_BLACK SN850X is a lot ahead in the Q32T16 condition. As for the maximum access speed/happy value, the WD_BLACK SN850X may be affected by some variables during the test. CrystalDiskMark did not show suppression, while ATTO Disk Benchmark was mostly slightly better.
In addition, in ezIOmeter, this test mode shows completely different results. Even if it is performed under QD 32 conditions, most FireCuda 530 SSDs are slightly faster than WD_BLACK SN850X, and the random write gap is even wider to about 10%. However, on the whole, most of the WD_BLACK SN850X can reach the officially declared value, and this design combination and firmware adjustment may not be more picky.
In the basic test part of PCMark, the system disk mode is won by WD_BLACK SN850X, and the total score and bandwidth are more than 14% apart. PCMark simulates many application software and file transfer and replication, and the detailed data is naturally different from each other. The final result is that the WD_BLACK SN850X is highly rated. In the 3DMark storage test, the WD_BLACK SN850X is comprehensively leading, living up to the name of its gaming and gaming positioning products.
In the final PCMark performance consistency test, the WD_BLACK SN850X was at the bottom of the total score and bandwidth, and was beaten by the FireCuda 530 SSD by as much as 77-80%. Observing the detailed data, it can be said that the WD_BLACK SN850X dirty disk speed drop occurs slightly faster and the drop rate is slightly more, but fortunately, the performance recovery performance is relatively outstanding. Therefore, the actual use may not be affected as much as the test data shows, and it will not constitute a big problem or even a defect.
All in all, the WD_BLACK SN850X has slightly improved reading and relatively improved writing, and leads the PCMark system disk and 3DMark storage tests, which is enough to be one of the new first choices for PCIe 4.0 NVMe high-end products. Although its performance is not comprehensive and outstanding, especially in the performance consistency and speed reduction, there is still room for improvement. Its characteristics may not have much impact on consumer applications. After all, this positioning product is not designed for intensive writing applications.
On the contrary, the PCIe 5.0 NVMe era is coming soon, coupled with the continuous drop in flash memory contract prices, many PCIe 4.0 NVMe products are on price cuts or even diving. The market price of the WD_BLACK SN850X is inevitably a bit high at this point in time when it was just launched. It depends on Western Digital and even the dealers, how much more attractive the future price strategy can add to the product.
