TurboVS
Western Digital WD Black SN7100 4TB specifications and in-depth review

Western Digital WD Black SN7100 4TB

Manufacturer: Western Digital

The Western Digital WD Black SN7100 4TB is a high-capacity M.2 NVMe solid-state drive built around the PCIe 4.0 interface, making it a capable option for users who need both substantial storage space and fast data throughput. It uses TLC NAND storage and operates through the Polaris 3 controller, which manages a 4TB usable capacity across four controller channels. The drive relies on Host Memory Buffer caching rather than dedicated DRAM, and it carries no integrated heatsink, so thermal management depends on the host system.

On the performance side, the SN7100 4TB is rated for sequential read speeds of 7250 MB/s and sequential write speeds of 6900 MB/s, while random read and write performance reach 900,000 IOPS and 1,350,000 IOPS respectively. It complies with NVMe version 1.4 and supports a maximum operating temperature of 85 °C. Western Digital rates the drive for 2400 terabytes written over its lifetime, and it is covered by a 5-year warranty. The drive does not include hardware-level AES encryption support or RGB lighting.

Pros
  • Sequential read speed of 7250 MB/s and write speed of 6900 MB/s indicate strong sustained throughput for large file transfers
  • Random write performance reaches 1,350,000 IOPS, reflecting solid responsiveness under heavy queue workloads
  • A TBW rating of 2400 terabytes points to substantial long-term write endurance for a 4TB drive
  • The 5-year warranty period offers meaningful coverage over an extended ownership period
  • A 4000GB capacity in the M.2 form factor provides significant storage without requiring a larger physical footprint
  • PCIe 4.0 with NVMe 1.4 support ensures compatibility with a wide range of modern motherboards
Cons
  • No hardware AES encryption support limits options for users who require data security at the drive level
  • Relies on Host Memory Buffer caching instead of dedicated DRAM, which can affect sustained performance consistency under prolonged heavy loads
  • The absence of an integrated heatsink means thermal management depends entirely on the host system
  • TLC NAND, while common at this capacity, offers lower write endurance per cell compared to MLC-based alternatives
Who is this for?

This drive suits users who regularly move or process large files at high throughput, such as those working with video editing projects, game libraries, or data-intensive applications where sustained sequential speeds of 7250 MB/s read and 6900 MB/s write translate to noticeably faster load and transfer times. The 4TB M.2 form factor makes it a practical fit for desktop builds or compatible laptops that need substantial internal storage without adding extra drives, and the 2400 TBW endurance rating means it can handle write-heavy workflows over several years without quickly exhausting its rated lifespan. Users running a PCIe 4.0-compatible system will be able to take full advantage of the drive's bandwidth capabilities.

Who is this NOT for?

Users with strict data security requirements will find this drive inadequate, as it offers no hardware-level AES encryption, meaning sensitive data cannot be protected at the drive itself without additional software solutions. Systems without a PCIe 4.0 interface will not be able to utilize the drive's full sequential performance potential, making it a poor match for older platforms. Additionally, users operating in thermally constrained environments should be aware that the drive lacks an integrated heatsink, so without adequate airflow or a motherboard-mounted heatsink, sustained workloads may push the drive toward its 85°C thermal limit.

Read speed:

sequential read speed 7250 MB/s
random read speed 900000 IOPS

The WD Black SN7100 4TB delivers a sequential read speed of 7250 MB/s, allowing large files to be read from the drive at a rapid sustained rate. For workloads involving many small, scattered data requests, the drive is rated at 900,000 random read IOPS, reflecting solid responsiveness under queue-heavy conditions.

Write speed:

sequential write speed 6900 MB/s
random write speed 1350000 IOPS

The WD Black SN7100 4TB is rated for a sequential write speed of 6900 MB/s, enabling large volumes of data to be written to the drive at a consistently high throughput. When handling fragmented or queue-intensive write operations, the drive reaches 1,350,000 random write IOPS, indicating strong performance under demanding mixed workloads.

Benchmarks:

General info:

type M2
SSD cache HMB (Host Memory Buffer)
Is an NVMe SSD ✓
NVMe version 1.4
internal storage 4000GB
controller Polaris 3 A101-000172-A1
SSD storage type TLC
PCI Express (PCIe) version 4
Controller channels 4
Terabytes Written (TBW) 2400
warranty period 5 years
Has an integrated heatsink ✕
maximum operating temperature 85 °C
bits of encryption supported 0
has RGB lighting ✕

The WD Black SN7100 4TB is an M.2 NVMe SSD operating over a PCIe 4.0 interface and conforming to NVMe version 1.4, with a total internal storage capacity of 4000GB built on TLC NAND. It is controlled by the Polaris 3 A101-000172-A1 chip across four controller channels, and uses Host Memory Buffer caching in place of dedicated onboard DRAM. The drive carries a TBW rating of 2400 terabytes and a maximum operating temperature of 85°C, and is backed by a 5-year warranty. It does not include an integrated heatsink, hardware AES encryption, or RGB lighting.

Final Verdict

The Western Digital WD Black SN7100 4TB presents a well-rounded case for users who need high-capacity M.2 storage with strong throughput credentials, particularly those running PCIe 4.0 systems where its 7250 MB/s sequential read speed and 2400 TBW endurance rating can be fully leveraged over an extended lifespan. Its reliance on Host Memory Buffer caching and the absence of hardware encryption and an integrated heatsink do place some constraints on its versatility, making it better suited to specific environments than universally applicable. That said, for desktop builders and power users who prioritize raw throughput and long-term write endurance at a meaningful capacity, the SN7100 4TB backed by a 5-year warranty represents a technically capable and dependable storage solution.

Popular Comparisons

Western Digital WD Black SN7100 4TB
Western Digital WD Black SN7100 4TB
VS
Adata XPG Mars 980 Blade 1TB
Adata XPG Mars 980 Blade 1TB
Western Digital WD Black SN7100 4TB
Western Digital WD Black SN7100 4TB
VS
Western Digital WD Black SN8100 1TB
Western Digital WD Black SN8100 1TB