WD Black SN770 review

Western Digital's mid-range PCIe 4 SSD offers decent overall performance for a decent price, but cheaper drives offer similar real-world performance.

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Our Verdict


Fast and reasonably priced, but there’s stiff competition above and below it.

It’s easy to get confused over WD’s naming schemes for its SSDs, but in general, if it’s Black it’s going to be fast, if it’s Blue it’s going to be not quite so fast and if it’s Red it’s going to have a decent endurance rating. The problem is that there are then different model names within those lineups. The Black SN770 we’re reviewing here isn’t the only Black series SSD to sit in WD’s arsenal, with the monstrous Black SN850 being one of our favorite PCI-E 4 SSDs.


As you’d expect, the Black SN770 also uses the PCI-E 4 interface, but at $125 for a 1TB drive, it’s only $12 cheaper than the flagship SSD. Storage prices fluctuate, of course, but we’d expect to see more of a difference at launch. Both SSDs come with a five-year warranty, and both have similar capacity options ranging from 500GB to 2TB for the SN850, and with an extra 250GB option for the SN770. They even have identical endurance ratings, with our 1TB sample good for 600 terabytes written (TBW), which is the same as the SN850.

It’s only when you get to the performance numbers that you see the difference between the two drives. The SN850 tops out at a claimed 7,000MB/sec read speed for all three capacities, while the SN770’s maximum claimed read speed hovers around 5,000MB/sec unless you dip down to 250GB where it drops to 4,000MB/sec. Write speeds follow a similar pattern with 5,000MB/sec for the SN770 at 1TB and 2TB, down to 4,000MB/sec at 500GB and 2,000MB/sec at 250GB. The SN850 meanwhile manages an extra 1,000MB/sec at 2TB and 1GB.

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Under the hood is a WD in-house four-channel controller with triple-level cell (TLC) NAND flash memory, but no DRAM for caching, with the SSD instead relying on system RAM and speedy BiCS5 112-layer TLC memory to ensure the real-world speeds are what you’d expect from a modern PCI-E 4 SSD.

Like the Kingston Fury Renegade M.2 SSD, there’s also no heatsink on the SN770, which can potentially lead PCI-E 4 SSDs to thermal throttle. However, with no heatsink attached, the SN770 peaked at the same 71°C temperature as the Kingston drive, but only after a back-to-back run of CrystalDiskMark as a stress test, during which it managed to still hit 5,226MB/sec read and 4,970MB/sec write speeds. Donning our motherboard’s heatsink saw no improvement in speeds, though, unlike the Kingston drive.

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Meanwhile, the SN770’s 4K random 32-queue-depth four-thread read speed of 2,255MB/sec was on par with the SN850, which managed 2,172MB/sec – a difference that’s within the margin of error for the test.

It was a similar situation for the 4K write speed of 1,932MB/sec, which was also more than a match for any other PCI-E 4 SSD we’ve tested, including the Kingston Fury Renegade. In AS-SSD, though, the Kingston SSD added 1,000MB/sec to the WD SN770’s sequential read speed.

WD Blue SN770 pros and cons


  • Excellent performance
  • Reasonable price
  • Doesn’t throttle without heatsink


  • Not much cheaper than SN850
  • Cheaper SSDs offer similar real-world performance
  • Average endurance rating

WD Blue SN770 specs

The WD Black SN770 specs list is:

Interface PCIe 4
Capacities 250GB, 500GB, 1TB, 2TB
Formatted capacities 931TB
Max sequential read/write speed 5150MB/s, 4850MB/s (2TB)
Max random read/write speed 740k/800k IOPS (2TB)
Controller WD in-house
Endurance rating 600TBW (1TB)
Warranty Five years

WD Blue SN770 price

Price: Expect to pay $180 for 2TB, $83 for 1TB

WD Blue SN770 review conclusion

Current pricing for the WD Black SN770 has it offering decent value for a PCI-E 4 M.2 SSD, thanks to its great performance in both sequential and random tests. Even at $125 for 1TB, though, you’d need some very good reasons to pick it over the WD Blue SN570, which costs $35 less and isn’t much slower in terms of real-world performance. Meanwhile, the WD Black SN850 is faster in sequential tests and costs only a little more money, making it a slightly better buy if you want the very best performance in all scenarios.

Looking for more storage upgrade options? Check out our guide to the best gaming SSD where we recommend options for every budget, with 1TB drives starting from just $55.