Western Digital announced it's about to deliver its own version of a 2230-format NVMe SSD in the form of the WD Black SN770M. The 2230 NVMe format brings a shorter PCB length and single-sided NAND memory, which make them particularly useful for space-constrained operating environments like the Steam Deck, one of the most popular handhelds. We'd argue it's best to buy slot-appropriate SSDs instead of resorting to cutting down 2280 or trying to cram in a 2242 form-factor SSDs, but your enthusiast mileage may vary.
The SN770M — M being likely short for "Mini" — has now been formally announced, and it seems to be a shortened clone of Western Digital's Black SN770 as both its operating speeds and controller architecture are the same. Sequential reads for the 2TB capacity version top out at 5,150 MB/s, while sequential writes come in a little under that at 4,850 MB/s. And isn't it impressive we can fit that into a 3cm, 2.8 gram chip?
Like all SSDs, maximum throughput for WD's Black 770M will vary according to capacities. The 2TB version and 1TB version are essentially equivalent in the speeds they can provide, though the 2 TB version does come in at a 50 MB/s lower sequential writing speed, compared to the 1TB version's 4,900 MB/s. Customers opting for the 500GB version of the SN 770M will find slightly lower but still very serviceable speeds: 5,000 MB/s reads and 4,000 MB/s writes. It's becoming increasingly difficult to find SSDs coming in at capacities lower than 500 GB; the 2230, 250 GB "equivalent" to the 2280-format Black SN770 is seemingly absent from the new form-factor's lineup.
SSD endurance too varies according to the customer's choice of capacity, but considering that even the 500GB version of the SN770M features a 300 TBW endurance, few users should ever run afoul of degrading NAND cells limiting their available disk space. Endurance for the SN770M scales linearly with total capacity, and it mirrors the SN770's endurance ratings and 600 TBW for the 1TB SSD and 1,200 TBW for the 2TB version.
Looking at how these products look exactly the same spec-wise except for the shortened form-factor, jokes could be done about SSD manufacturers taking scissors to their own products while charging more for them. This is true of WD's SN770M as well. While the 2TB 2280 SSD form-factor can be bought at an average of €0.05/GB, the same 2TB capacity within the "mini" 2230 SSD lineup costs three times as much at €0.15/GB. But that's the way the market works: Fewer options within the 2230 form-factor and an increasing appetite thanks to the proliferation of handhelds and other space-constrained hardware mean higher prices.
All the SN770M SSDs cost more per GB than their full-sized 2280 counterparts, with the 500GB coming in at €100, compared to an average €40 for the 2280 version. The 1TB capacity will double the cost as well, at €200 against 50€ for the 1TB 2280 SSD, and the 2TB will come in at a 299€ — more than triple the price of the 100€, 2TB 2280 form-factor drive. If you need a 2230 drive with lots of capacity, though, your options are relatively limited.