The SN7100 is the drive to buy when efficiency and random read speed matter most — laptops, handhelds, and small builds get a cool, single-sided SSD that loads games fast and sips power. On a desktop, the case weakens: random writes trail DRAM drives, and the SN850X sometimes costs the same while matching it in several tests. Buy the SN7100 when its price undercuts the SN850X or when the device runs hot and tight; otherwise compare the two first. To see the current deal, check the current price on Amazon before buying.
— THE VERDICT · JUDGEANY EDITORSWhat the SN7100 is
The WD Black SN7100 is SanDisk's successor to the popular SN770: a single-sided M.2 2280 PCIe Gen4 drive with no DRAM, using host memory buffer (HMB) technology and SanDisk's Polaris 3 controller paired with Kioxia 218-layer BiCS8 TLC NAND. Rated speeds run up to 7,250 MB/s read and 6,900 MB/s write on the 1 TB and 2 TB models, with a 5-year warranty and 600 TBW of endurance per terabyte. Capacities run from 500 GB to 4 TB, and the drive ships without a heatsink. This review aggregates SanDisk's specifications, Tom's Hardware's benchmark review, and PC Gamer's 1 TB review. JudgeAny runs no test lab; the scores below are editorial judgments built on that evidence.
Speed: sequential numbers hold, random reads shine
PC Gamer's test bench recorded 7,116 MB/s read and 6,820 MB/s write in CrystalDiskMark on the 1 TB model — close to the rated figures, and slightly ahead of the SN850X's 8 TB variant on both numbers. The standout was random 4K read performance: 101 MB/s, which PC Gamer called demolishing every drive it had tested, ahead of even the PCIe 5.0 Crucial T700's 81 MB/s. Tom's Hardware's DiskBench transfer tests told a similar story, with the SN7100 matching or beating strong drives like the 990 Pro on file transfers. For game loading and everyday transfers, the drive delivers what the box promises.
Efficiency: the real reason to pick it
Tom's Hardware called the SN7100's power efficiency the best it had ever seen at the time of review, and SanDisk claims up to 100% better maximum-speed power efficiency than the 1 TB SN770, alongside up to 35% better performance. That matters most in laptops and handhelds, where a single-sided, cool-running drive leaves more thermal and battery headroom — PC Gamer also flagged low temperatures as a plus. On a desktop with strong airflow, efficiency matters less, and that is where the SN7100's case gets thinner.
The caveats: DRAM-less writes and the price question
The HMB design has a weak spot, and both reviewers found it. PC Gamer's random 4K write figure of 276 MB/s trailed the SN850X by a healthy margin, and it also recorded slower load times than expected in relative terms. Tom's Hardware's verdict was blunter: the drive falls short in all-around performance and was priced significantly above the competitive range at popular capacities, at times costing more than the SN850X itself — a drive that matches or beats it in some tests. The WD Black Dashboard software (Windows only) covers monitoring and firmware, but it does not close the value gap when the older flagship costs the same.
Where the evidence disagrees
Tom's Hardware pegged the SN7100 as above average only, held back by price and all-around performance, while PC Gamer was warmer, calling it a fine place to start for a gaming PC or console. The gap is about what you weight: Tom's leans on price against the SN850X, PC Gamer leans on read performance and temperatures. Both agree on the drive's shape — superb efficiency and random reads, unremarkable writes, and a price that has to be right. Check the SN850X's current price alongside this one before deciding.
Who should buy it
The SN7100 suits laptop and handheld owners first — Steam Deck, ROG Ally, and thin gaming laptops benefit most from its single-sided layout, low heat, and efficiency. Desktop builders chasing maximum all-around speed should compare it against the SN850X and the Samsung 990 Pro, especially if those cost the same. One compatibility note: the drive is M.2 2280, so check that the device takes that length before ordering. To see the current deal, check the current price on Amazon before buying.