WD_BLACK SN770M
M.2 2230 Form Factor | PCle 4.0 Performance | Gaming-Optimized Firmware
Introduction
The WD_BLACK SN770M NVMe SSD represents a specialized storage solution engineered for compact computing devices and handheld gaming systems. As the first M.2 2230 SSD from a major storage brand targeting gamers, it addresses growing demand for high-performance storage in space-constrained environments like the Steam Deck and ASUS ROG Ally. With PCIe Gen4 capabilities and capacities up to 2TB, this drive bridges the gap between portability and desktop-grade performance.
Product Overview
Designed as a direct upgrade for M.2 2230-compatible systems, the SN770M combines Western Digital’s 112-layer BiCS5 TLC NAND with a proprietary controller in a 22x30mm form factor. Targeted at users of handheld gaming PCs, ultraportable laptops, and small-form-factor builds, it emphasizes rapid game installations, reduced load times, and expanded storage capacity without physical bulk. The drive operates on PCIe 4.0 x4 lanes while maintaining backward compatibility with PCIe 3.0 hosts.
Key Features
M.2 2230 Form Factor
At 30mm length, the SN770M fits devices incompatible with standard 2280 SSDs, including Valve’s Steam Deck and Microsoft Surface laptops. This compact design retains full PCIe 4.0 x4 bandwidth through optimized component integration.
PCIe 4.0 Performance
Delivering sequential reads up to 5,150 MB/s and writes reaching 4,900 MB/s (1TB/2TB models), the drive exceeds typical handheld storage performance by 300-400%. Western Digital’s nCache 4.0 technology accelerates small-file operations, while HMB (Host Memory Buffer) leverages system RAM to compensate for its DRAM-less architecture.
Gaming-Optimized Firmware
Microsoft DirectStorage support enables GPU-direct asset loading, reducing CPU overhead in modern games. The Western Digital Dashboard utility allows performance tuning and firmware updates, though it remains Windows-exclusive.
Performance Analysis
Sequential Speeds
In optimal PCIe 4.0 environments, the SN770M achieves 5,150 MB/s reads and 4,850 MB/s writes (2TB model). These figures place it within 15% of premium 2280 SSDs despite its size constraints. On PCIe 3.0 systems like the Steam Deck, performance caps at ~3,500 MB/s due to interface limitations[3][5].
Random Performance
The drive sustains 740K IOPS (4K QD32 reads) and 800K IOPS (4K QD32 writes), outperforming many QLC-based competitors. HMB implementation reduces write latency by 40% compared to DRAM-less designs without host buffer support[8][5].
Thermal Management
Using a single-sided layout and 16nm controller, the SN770M exhibits peak temperatures of 78°C under sustained loads. While throttling occurs after 4 minutes of continuous writes, typical gaming workloads rarely trigger thermal limits. Passive heatsinks are compatible but rarely required in handheld use cases[8][3].
Compatibility
Steam Deck and Handheld PCs
Fully compatible with Steam Deck’s M.2 2230 slot after disassembly. Installation requires PCIe 3.0 x4 compatibility, limiting sequential speeds to 3,500 MB/s but maintaining strong random performance for game assets[2][5].
Desktops and Laptops
Requires M-key M.2 slots supporting 2230/2242/2260/2280 lengths (via adapter brackets). Not recommended for PCIe 5.0 systems due to interface mismatch. Compatible with Linux distributions using kernel 5.8+ for full NVMe support[3][6].
Advantages and Limitations
Strengths
Capacity Scaling: 2TB model stores 50+ modern AAA titles, doubling typical handheld storage
Energy Efficiency: Consumes 35% less power than comparable Phison E21T-based drives during active use
Constraints
HMB Dependency: Write performance drops 60% on systems without Host Memory Buffer support
Endurance Rating: 600TBW per TB trails premium TLC drives by 25%, though sufficient for gaming workloads
Conclusion
The WD_BLACK SN770M establishes itself as the definitive storage upgrade for M.2 2230-constrained devices, particularly handheld gaming PCs. While not suitable for PS5/Xbox Series consoles due to form factor limitations, it delivers exceptional value for Steam Deck owners and ultraportable laptop users needing reliable high-speed storage. The drive’s balance of capacity, thermal characteristics, and DirectStorage optimization makes it ideal for gamers prioritizing load times and installation flexibility.
Works Cited
"Data Sheet: WD_BLACK SN770M NVMe SSD." Western Digital, documents.westerndigital.com/content/dam/doc-library/en_us/assets/public/western-digital/product/internal-drives/wd-black-ssd/data-sheet-wd-black-sn770m-nvme-ssd.pdf.
Jacobi, Jon L. "WD Black SN770M Review: A Fast, Spacious SSD for Your Steam Deck." PCWorld, www.pcworld.com/article/2095268/wd-black-sn770m-nvme-ssd-review.html.
"WD Black SN770M 2230 SSD Review." StorageReview, www.storagereview.com/review/wd-black-sn770m-2230-ssd-review.
