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Western Digital WD Black SN7100 4TB
Western Digital WD Black SN8100 1TB

Western Digital WD Black SN7100 4TB Western Digital WD Black SN8100 1TB

Common Features

  • ✓ Both products are M2 type.
  • ✓ Both products are NVMe SSDs.
  • ✓ Both products use TLC SSD storage type.
  • ✓ Both products come with a 5-year warranty.
  • ✓ Neither product has an integrated heatsink.
  • ✓ Neither product has RGB lighting.
  • ✓ Both products use PCIe technology.
  • ✓ Both products have an SSD cache.
  • ✓ Both products support NVMe version 1.4 or higher.

Main Differences

  • • Sequential read speed is 7250 MB/s on Western Digital WD Black SN7100 4TB and 14900 MB/s on Western Digital WD Black SN8100 1TB.
  • • Random read speed is 900000 IOPS on Western Digital WD Black SN7100 4TB and 1600000 IOPS on Western Digital WD Black SN8100 1TB.
  • • Sequential write speed is 6900 MB/s on Western Digital WD Black SN7100 4TB and 11000 MB/s on Western Digital WD Black SN8100 1TB.
  • • Random write speed is 1350000 IOPS on Western Digital WD Black SN7100 4TB and 2400000 IOPS on Western Digital WD Black SN8100 1TB.
  • • SSD cache is HMB (Host Memory Buffer) on Western Digital WD Black SN7100 4TB and DRAM cache on Western Digital WD Black SN8100 1TB.
  • • NVMe version is 1.4 on Western Digital WD Black SN7100 4TB and 2 on Western Digital WD Black SN8100 1TB.
  • • Internal storage is 4000GB on Western Digital WD Black SN7100 4TB and 1000GB on Western Digital WD Black SN8100 1TB.
  • • Controller is Polaris 3 A101-000172-A1 on Western Digital WD Black SN7100 4TB and Silicon Motion SM2508 on Western Digital WD Black SN8100 1TB.
  • • PCI Express (PCIe) version is 4 on Western Digital WD Black SN7100 4TB and 5 on Western Digital WD Black SN8100 1TB.
  • • Controller channels are 4 on Western Digital WD Black SN7100 4TB and 8 on Western Digital WD Black SN8100 1TB.
  • • Terabytes Written (TBW) is 2400 on Western Digital WD Black SN7100 4TB and 600 on Western Digital WD Black SN8100 1TB.
Specs Comparison
Western Digital WD Black SN7100 4TB

Western Digital WD Black SN7100 4TB

Western Digital WD Black SN8100 1TB

Western Digital WD Black SN8100 1TB

Read speed:
sequential read speed 7250 MB/s 14900 MB/s
random read speed 900000 IOPS 1600000 IOPS

The Western Digital WD Black SN7100 4TB and the WD Black SN8100 1TB differ significantly in their read speeds. For sequential read speed, the SN7100 offers 7250 MB/s, while the SN8100 provides a much faster 14900 MB/s. This shows a clear advantage in sequential read performance for the SN8100.

When it comes to random read speed, the SN7100 delivers 900,000 IOPS, while the SN8100 achieves 1,600,000 IOPS. Again, the SN8100 shows higher performance in random reads, with nearly double the IOPS of the SN7100.

Overall, while both products offer strong read speeds, the SN8100 outpaces the SN7100 in both sequential and random read speeds, offering nearly twice the performance in each category.

Write speed:
sequential write speed 6900 MB/s 11000 MB/s
random write speed 1350000 IOPS 2400000 IOPS

The Western Digital WD Black SN7100 4TB and the WD Black SN8100 1TB show notable differences in their write speeds. For sequential write speed, the SN7100 offers 6900 MB/s, whereas the SN8100 delivers a faster 11,000 MB/s. This gives the SN8100 a clear edge in sequential write performance.

In terms of random write speed, the SN7100 provides 1,350,000 IOPS, while the SN8100 outperforms it with 2,400,000 IOPS. The SN8100 thus shows significantly higher random write performance as well.

Overall, the SN8100 leads in both sequential and random write speeds, offering substantially better write performance compared to the SN7100 in both categories.

General info:
type M2 M2
SSD cache HMB (Host Memory Buffer) DRAM cache
Is an NVMe SSD ✓ ✓
NVMe version 1.4 2
internal storage 4000GB 1000GB
release date March 2025 May 2025
controller Polaris 3 A101-000172-A1 Silicon Motion SM2508
SSD storage type TLC TLC
PCI Express (PCIe) version 4 5
Controller channels 4 8
Terabytes Written (TBW) 2400 600
warranty period 5 years 5 years
Has an integrated heatsink ✕ ✕
has RGB lighting ✕ ✕

The Western Digital WD Black SN7100 4TB and the WD Black SN8100 1TB share some similarities, such as both being M.2 NVMe SSDs with TLC storage type and a 5-year warranty period. However, they differ in various other aspects. The SN7100 has 4000GB of internal storage, while the SN8100 offers only 1000GB of internal storage. This gives the SN7100 significantly more capacity for storage-heavy tasks.

The SN7100 utilizes a Polaris 3 A101-000172-A1 controller with 4 controller channels, while the SN8100 uses a Silicon Motion SM2508 controller with 8 controller channels. Additionally, the SN7100 supports PCIe 4.0, whereas the SN8100 supports PCIe 5.0, providing the latter with a higher potential for throughput.

In terms of other features, the SN7100 has HMB (Host Memory Buffer) as its SSD cache, while the SN8100 is equipped with a DRAM cache. Both products have no integrated heatsink or RGB lighting. The SN7100 also offers a higher Terabytes Written (TBW) of 2400, compared to the SN8100’s 600, indicating a difference in expected endurance for these drives.

Comparison Summary

This is a specification comparison between Western Digital WD Black SN7100 4TB and Western Digital WD Black SN8100 1TB. Both models are M2 NVMe SSDs with a 5-year warranty and use TLC storage type, but differ in several areas. The sequential read speed is 7250 MB/s on the SN7100 4TB and 14900 MB/s on the SN8100 1TB, while the random read speed is 900000 IOPS on the SN7100 4TB and 1600000 IOPS on the SN8100 1TB. The internal storage capacity is 4000GB on the SN7100 4TB and 1000GB on the SN8100 1TB. The SN7100 4TB uses HMB (Host Memory Buffer) for SSD cache, while the SN8100 1TB uses DRAM cache. Additionally, the SN7100 4TB has a PCIe 4 interface, whereas the SN8100 1TB supports PCIe 5.