Samsung 9100 Pro 8TB (With Heatsink) VS Western Digital WD Black SN8100 4TB

In sequential read performance, these two drives are virtually neck-and-neck. The WD Black SN8100 4TB edges ahead at 14900 MB/s versus 14800 MB/s for the Samsung 9100 Pro 8TB — a difference of just 100 MB/s, or less than 1%. At this tier of performance, both drives are operating at the cutting edge of current PCIe Gen 5 bandwidth, and in practice, no real-world workload would allow a user to perceive this gap.

The random read story follows the same pattern. The SN8100 leads again with 2,300,000 IOPS compared to the 9100 Pro's 2,200,000 IOPS — a 100,000 IOPS or roughly 4.5% difference. Random read performance matters most in latency-sensitive workloads like OS responsiveness, database queries, and loading many small files simultaneously. A 4–5% advantage here is marginally more meaningful than the sequential gap, though both figures are exceptionally high and well beyond what most consumer applications can fully saturate.

Overall, the WD Black SN8100 4TB holds a technical edge in both read metrics, but the margin is so slim that it amounts to a near-tie in any practical scenario. Users choosing between these drives should weigh other spec groups — such as write performance, thermal behavior, or capacity — rather than treating this read speed difference as a decisive factor.

Write performance is where these two drives begin to diverge in an interesting way. The WD Black SN8100 4TB takes the sequential write lead at 14000 MB/s versus 13400 MB/s for the Samsung 9100 Pro 8TB — a roughly 4.5% advantage that is more tangible than the read gap. For sustained large-file transfers, video editing timelines, or backup operations involving tens or hundreds of gigabytes, the SN8100 will complete those tasks measurably faster.

Flip to random writes, however, and the Samsung reclaims the lead decisively — 2,600,000 IOPS against the SN8100's 2,400,000 IOPS, an 8.3% margin. This matters in write-heavy transactional workloads: think virtual machines writing lots of small state files, compile jobs touching thousands of incremental objects, or NVMe-accelerated database writes. The 9100 Pro's advantage here is the more operationally significant delta of the two metrics.

Write performance ends up split between the two drives, making the ″winner″ dependent on use case. The SN8100 has the edge for throughput-oriented, large-block writing, while the Samsung 9100 Pro pulls ahead where high-concurrency, small-block write responsiveness is the priority. Neither holds an across-the-board advantage in this category.

PassMark scores synthesize a range of real-world storage behaviors — sequential throughput, random access, and mixed workloads — into a single composite number, making them a useful holistic tiebreaker when individual specs tell a split story. Here, the WD Black SN8100 4TB scores 90,689 against the Samsung 9100 Pro 8TB's 82,109 — a gap of roughly 10.4%.

That margin is meaningful. A 10% composite advantage suggests the SN8100 consistently outperforms the 9100 Pro across the blend of tasks PassMark exercises, not just in one isolated metric. This aligns with the sequential write lead the SN8100 showed in its individual specs, and implies that in aggregate, everyday system responsiveness and throughput will favor the WD drive.

The PassMark result gives the SN8100 a clear overall edge in this benchmark category. For users who want a single data point that captures broad drive performance rather than cherry-picking individual metrics, this score reinforces the WD Black as the stronger all-round performer of the two — at least at the capacities being compared here.

At the foundation, these two drives share the same core architecture: both are M.2 NVMe SSDs running PCIe Gen 5 with NVMe 2.0, backed by DRAM cache, built on TLC NAND, and equipped with 8-channel controllers. That common platform explains why their raw performance numbers sit so close together. The meaningful differences emerge in capacity, endurance, and a few practical considerations.

The most significant split is storage size and longevity. The Samsung 9100 Pro ships at 8TB with a 4,800 TBW endurance rating, while the WD Black SN8100 offers 4TB and 2,400 TBW — both exactly half. This is proportional and expected, so neither drive is more durable per terabyte; the Samsung simply offers more of everything in absolute terms. For users who need a single high-capacity NVMe drive, the 9100 Pro is the only option of the two that reaches 8TB. The integrated heatsink on the Samsung is also a practical differentiator — it helps manage thermals out of the box, which matters in sustained workloads or builds with limited airflow, whereas the SN8100 relies on the system or aftermarket cooling.

Both carry identical 5-year warranties, which signals comparable manufacturer confidence in long-term reliability. The controller difference — Samsung's proprietary Presto versus Silicon Motion's SM2508 — is architecturally notable, as in-house controllers can be more tightly tuned to the NAND they accompany, though the performance data across other spec groups is the real measure of that. Overall, the Samsung 9100 Pro holds a general-info advantage for users prioritizing raw capacity and thermal management, while the WD SN8100 is the leaner, more compact option for those who don't need the extra storage headroom.