WD Black SN7100 vs WD Black SN850X: Which One Should you Choose?

The WD Black SN850X is one of the most popular SSDs on the market. It leads the Gen 4.0 category alongside the very popular Samsung 990 Pro. The SN7100, on the other hand, is a mid-range DRAM-less SSD targeting a broader budget-segment audience. It is suitable for light workloads, while the SN850X is more targeted toward the high-end of the spectrum. SN850X is also a popular choice among gamers because of its dedicated Game Mode 2.0.

Choosing between these two is easy. In terms of technical specs and sustained performance, the SN850X has better features to offer. It is equipped with DRAM, a major concern when choosing an SSD. The SN850X has the 8TB variant, which the SN7100 lacks, and this could be a major selection criterion for those seeking higher storage capacity. Although the 1TB, 2TB, and 4TB SN850X are older (released in 2022), they are among the most thoroughly tested and respected products on the market. The 8TB variant, however, was released later in 2024 with an upgraded controller, i.e., Triton MP16+ B2.

The issue with the SN850X is that it is an old drive, and even though the SN7100 is a mid-range drive without DRAM, it beats the SN850X in most benchmarks. The SN7100 comes with the latest DRAM-less controller (Polaris 3), which runs cooler and has better 4K performance. It will also help you save some money compared to the SN850X, but there are solid reasons to pick the SN850X, even though it is expensive. So, we are going to talk about every aspect of it. I assure you, by the end of this article, you will be able to make the final decision without any confusion.

WD Black SN850X vs SN7100 Specifications

As discussed earlier, the Polaris 3 comes with good random read/write performance. So, you can see a higher theoretical random write speed with the SN7100 as compared to that of the SN850X. In all other areas, i.e., sequential read/write and random read, the SN850X claims better performance. Again, the SN850X comes with its DRAM, whose size will be discussed later in the article, and we have already covered the controller a little bit.

The 8TB variant with the SN850X is an advantage, but the 500GB SN7100 is also good for people looking for less storage. However, most people are curious to know the difference in the real-world performance, so let’s jump right into the benchmark scores.

Benchmark Scores

These benchmarks are for the 2TB versions of both SSDs for a fair comparison. The benchmark scores are from Tom’s Hardware and other third-party websites; the links to the respective pages are given at the end of the article.

PCMark 10 Full Storage Benchmark

The PCMark 10 Storage benchmark measures the performance of a storage device by simulating real-world workloads, including common tasks like booting Windows, launching applications (e.g., Adobe Photoshop, Microsoft Excel), file transfers, and game load times. It uses actual application traces rather than synthetic tests to evaluate how a storage device handles read/write operations, access times, and data throughput under realistic conditions. There are two types of tests, i.e., Full and Quick Drive benchmark, where the Full Benchmark tests the drive’s capabilities as the primary drive while Quick Benchmark tests it as the secondary drive. We are comparing the Full Drive benchmark scores here.

The WD Black SN7100 outperforms the WD Black SN850X in the PCMark 10 storage benchmark with a score that is 18.6% higher (4561 vs. 3846), bandwidth that is 21.1% higher (734 MB/s vs. 606 MB/s), and latency that is 13.9% lower (37.0 µs vs. 43.0 µs). Now, why this is happening is mainly because of better random performance from the SN7100’s controller. Also, it is well-optimized for sustained workloads, and it goes head-to-head with other popular SSDs in PCMark 10 scores, like the Samsung 990 Pro and Crucial T500.

3DMark Storage Benchmark for Gamers

The WD Black SN850X outperforms the SN7100 with a score 9.8% higher (4466 vs. 4068), bandwidth 7.0% higher (760 MB/s vs. 710 MB/s), and latency 11.1% lower (40 µs vs. 45 µs) in the 3DMark Benchmark. These scores are without the dedicated game mode turned on in the SN850X. So, as the company promotes it, the SN850X surely offers good performance in gaming scenarios.

CrystalDiskMark Sequential and Random Benchmark

CDM Sequential benchmarks test how fast large blocks of data (typically 1MB or more) can be read from or written to the drive in a continuous stream. This is ideal to test a drive for tasks like copying large files. The random benchmarks measure the drive’s ability to handle small, scattered blocks of data (e.g., 4KB), simulating real-world tasks like OS operations or application launches. These tests help evaluate both raw throughput and responsiveness under various usage patterns. So, let’s compare these results.

In CrystalDiskMark sequential benchmarks, the performance is almost similar with little variations. The SN850X has a 4% higher peak sequential QD1 read speed (5214 MB/s vs. 5012 MB/s), while the SN7100 leads in peak sequential QD1 write speed by 1% (6040 MB/s vs. 5982 MB/s). At higher queue depths (QD8), the SN7100 outperforms the SN850X by 2.2% in read speed (7137 MB/s vs. 6982 MB/s) and 2.8% in write speed (6860 MB/s vs. 6676 MB/s). Overall, the SN7100 shows slightly better sustained throughput at high queue depths, while the SN850X edges ahead in low queue depth read speeds.

In the CDM random benchmarks, the WD Black SN7100 and SN850X show distinct strengths. At low queue depth (QD1), the SN7100 has 39% higher read IOPS (31,836 vs. 22,853), while the SN850X has a slight 2.7% advantage in write IOPS (91,200 vs. 88,816). At high queue depth (QD256), the SN850X leads in read IOPS by 17.5% (1,197,374 vs. 1,018,696), but the SN7100 dominates in write IOPS with a 19.3% advantage (1,402,722 vs. 1,175,695). You can see a pattern here. The SN7100 is good at write-heavy workloads and low-QD responsiveness, while the SN850X is optimized for high-QD read performance.

Transfer Rate

These are raw file movement benchmarks that help you understand any SSD’s capabilities for moving large files. These tests include copying, pasting, and moving files from and to the drive. Let’s see the results.

It has a 12.2% higher copy transfer rate (2050 MB/s vs. 1827 MB/s), a 18.8% higher write transfer rate for a 50GB folder (2192 MB/s vs. 1845 MB/s), and a slightly higher read speed for a 6.5GB zip file (3981 MB/s vs. 3936 MB/s, a 1.1% difference).

Power Consumption and Efficiency

The SN7100 offers 62.4% higher efficiency in MB/s per watt during a 50GB file copy (729 vs. 449), 25% lower average power consumption during the transfer (3W vs. 4W), and 13.8% lower idle power draw (969 mW vs. 1124 mW). Additionally, its maximum power consumption is 40% lower (4.10W vs. 6.83W). These figures indicate that the SN7100 is significantly more power-efficient and runs cooler.

SN7100’s HMB and a rant

We just saw that the SN850X lost in most of the benchmarks except the 3DMark test for gamers. It is acceptable because the SN850X’s refinements are targeted mainly for gaming-related tasks, for example, the Game Mode 2.0 here. Now, most people think having no DRAM in an SSD is a bad thing. But this prejudice has started vanishing over time. We are now capable of designing much better firmware and algorithms to have the highest HMB hit rates. So, when we have the cheap SSDs like the SN7100 beating the old leaders like the SN850X, we often think, Why do we have to pay the premium just for the component that makes the SSD expensive and run hotter?

We have been believing the fact that DRAM-Less SSDs have slower random read/write performance, but we are now seeing these SSDs leading the benchmark tables and beating the DRAM drives with ease. But, still, there are issues with the DRAM-less design, mainly related to latency and endurance. It is a compromise, not with the performance anymore, but the things that we generally do not discuss a lot. In this comparison, even though the SN7100 has better performance, I would still go for the SN850X if I had to think long-term and have enough money to spend on it. DRAM-less designs are now prevalent, but they have hidden costs behind that cost-cutting that the brands does.

TBW, DWPD, and Warranty

In the matching variants of both the drives, the TBW is exactly the same. Warranty period, MTBF, and DWPD are also the same. So, there is nothing to compare here.

Technical Specifications

The WD Polaris 3 in the SN7100 is newer and modern, while the WD G2 or Triton MP16+ B2 (for 8TB) is essentially an evolution of older WD Black tech. The DRAM-less design of the SN7100 means a cheaper price but slightly worse sustained performance. The SN850X, with its own DRAM, is much better for heavy workloads and consistency.

SN7100’s NAND is newer, faster (3,600 MT/s vs. 1,200 MT/s). So while its controller setup is leaner, its raw NAND throughput crushes that of the SN850X. However, the SN7100 lacks any encryption. Overall, specification-wise, the SN7100 is much more advanced while the SN850X seems a little outdated but still much more tested and proven in the industry.

Price Difference

By the time I am writing this article, the SN850X 1TB (without heatsink) is available for $94.99 on Newegg. The 1TB SN7100 is available for $74.59. The 2TB SN850X can be purchased for $148.99, while the 2TB SN7100 is for $125.99. So, this is the general difference in the prices. However, prices keep changing, and in sales seasons, they may drop and vary even more. So, I recommend checking them in real-time, though it is certain that the SN7100 will always be cheaper than the SN850X.

Which Gen 4.0 SSD to choose: WD Black SN7100 or SN850X?

If you are tight on a budget and still want the best drive out there, you should go for the SN7100. However, if you are looking for an SSD that has DRAM, encryption, and a dedicated gaming mode, the SN850X is the right pick for you. For most people, the SN7100 will be a good choice if their work includes office work, creating tasks, and light gaming. Most people would hardly notice any difference in the performance due to the lack of DRAM because the HMB technology has become so advanced. However, those who are obsessed with the specifications, the SN850X has got you covered with everything.

Another place where the SN7100 can be a good choice is for laptop upgrades. It runs cooler and consumes less power than the SN850X. In simple words, the SN7100 is good for most people, while the SN850X is best for gaming and heavy workloads where DRAM can be helpful.

Some other Gen 4.0 alternatives to look for are Samsung 990 Pro, Crucial T500, and WD Black SN5000.