WD Black SN7100 review: This record-breaking SSD is a new gaming champion

At a glanceExpert's Rating

Pros

Top-notch HMB performance

Affordable

Sexy name

Cons

Slower random performance than DRAM designs

Our Verdict
The WD Black SN7100 was the fastest PCIe 4.0/host memory buffer design we’ve tested. It’s our number one for the average user.

Price When Reviewed
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The WD Black SN7100 is the latest of the company’s NVMe SSDs marketed for the gaming community. Hence the “Black” in the moniker.

The big pitch is that games have grown enormous so you need a larger SSD. No argument there, but WD might’ve highlighted the excellent performance more saliently.

Read on to learn more about this killer drive, and then see our roundup of the best PCIe 4.0 SSDs for comparison.

What are the WD Black SN7100’s features?

The Black SN7100 is a single-sided, 2280 (22mm wide, 80mm long) PCIe 4.0, NVMe SSD featuring a Sandisk (a subsidiary of WD) A101-000172-A1 controller and layered BiCS8 NAND — the latest.

It’s a host memory buffer (DRAM-less) design, meaning it uses your device’s system memory for primary caching duties. A certain amount of NAND will be written as single-layer cell (1-bit) for secondary cache duty.




The retail box for the 2TB WD Black SN7100.

The SN7100 is warrantied for five years and the TBW rating (guaranteed terabytes that may be written) is 600 per TB of capacity — average for a budget TLC SSD. While users are unlikely to hit that TBW, the worst that can happen is the drive will simply go into read-only mode. You won’t lose any data.

How much is the WD Black SN7100?

At the time of this writing, the WD Black SN7100 is priced on Amazon as follows: 500GB capacity for $60, 1TB for $80, and 2TB (tested) for $160. It’s not the cheapest SSD around, but certainly competitive in that regard.

How fast is the WD Black SN7100?

In testing with synthetic benchmarks, the 2TB Black SN7100 proved the fastest PCIe 4.0 host memory buffer (HMB) design SSD we’ve put through the wringer so far. Not by a huge margin, but noticeably, as you can see in the CrystalDiskMark 8 sequential transfer numbers below.




The SN7100 mastered its competitors in the CrystalDiskMark 8 sequential tests. Longer bars are better.

Random performance under CrystalDiskMark 8 was also excellent. Consider the Lexar NM790’s performance in this test an aberration as it was otherwise a very fast performer.




The SN7100 again was top dog CrystalDiskMark 8’s random 4K tests. Longer bars are better.

While still fast at our 48GB transfers, the SN7100 was not the fastest. These tests have a margin of error of 2 or 3 seconds.




This is a good aggregate 48GB transfer time for the SN7100, but not the fastest of the four. Shorter bars are better.

The margin of error in the 450GB write is also several seconds, but certainly not the 20-second gap that the Kingston NV3 pulled on the other SSDs. Host memory buffer implementations are far better than they were at first, but still vary.

The 2TB Black SN7100 proved the fastest PCIe 4.0 host memory buffer (HMB) design SSD we’ve put through the wringer so far.

The reason for the Teamgroup MP44’s slower 450GB performance was a rather parsimonious helping of secondary cache.




This is a very good 450GB write time from the SN7100, though not record breaking. Shorter bars are better.

Several subsequent 450GB writes showed what I’d expect when writing modern TLC natively — a relatively stable 500MBps to nearly 1GBps.




This is more the type of slowdown I expect from modern TLC NAND — 500MBps to 1GBps.

Should you buy the WD Black SN7100?

I’m calling the SN7100 top dog in the PCIe 4.0/HMB category. For everyday use — fantastic.

This article was edited on February 7th, 2025 to remove discussion of an issue that was likely the fault of the secondary drive on our test bed.

How we test

Drive tests currently utilize Windows 11, 64-bit running on an X790 (PCIe 4.0/5.0) motherboard/i5-12400 CPU combo with two Kingston Fury 32GB DDR5 4800MHz modules (64GB of memory total). Both 20Gbps USB and Thunderbolt 4 are integrated to the back panel and Intel CPU/GPU graphics are used. The 48GB transfer tests utilize an ImDisk RAM disk taking up 58GB of the 64GB of total memory. The 450GB file is transferred from a 2TB Samsung 990 Pro which also runs the OS.

Each test is performed on a newly NTFS-formatted and TRIM’d drive so the results are optimal. Note that in normal use, as a drive fills up, performance may decrease due to less NAND for secondary caching, as well as other factors. This can be less of a factor with the current crop of SSDs with far faster late-generation NAND.

Caveat: The performance numbers shown apply only to the drive we were shipped and to the capacity tested. SSD performance can and will vary by capacity due to more or fewer chips to shotgun reads/writes across and the amount of NAND available for secondary caching. Vendors also occasionally swap components. If you ever notice a large discrepancy between the performance you experience and that which we report, by all means, let us know.