SanDisk WD Blue SN5100: Gen4 Storage for Everyday Workloads

A mostly solid SSD built for those not yet ready to jump into Gen5.

SanDisk’s WD Blue SN5100 NVMe SSD is the newest addition to the company’s lineup. While Gen5 SSDs are beginning to take over the high-end market, most consumers don’t yet have systems that support them. That makes Gen4 options, such as the SN5100, a smart and practical choice for users who want solid speed without overspending. SanDisk positions it as a drive for creators, engineers, and professionals who require dependable storage for demanding tasks, such as AI-assisted workloads, media-intensive projects, and daily productivity. In practice, though, the SN5100 sits closer to the budget side of the market.

WD Blue SN5100 Features

The SN5100 is available in capacities ranging from 500GB to 2TB and utilizes SanDisk’s QLC 3D CBA NAND, along with nCache 4.0, to help sustain write performance during heavier data transfers. Its rated performance is solid for a Gen4 client drive. The 1TB and 2TB models are listed with sequential read speeds up to 7,100MB/s and write speeds up to 6,700MB/s. Random reads hit up to 1,000,000 IOPS, while writes peak at 1,300,000 IOPS. The 500GB version is slightly lower, with read speeds of 6,600MB/s and write speeds of 5,600MB/s, and IOPS of 660,000 for reads and 1,100,000 for writes. SanDisk claims a 30% speed bump over the SN5000 series, although actual results may vary depending on your setup. We’ll dig into that further in our benchmarks below.

The SN5100’s NAND is SanDisk’s 3D QLC CBA, which fits more bits per cell to increase storage density. QLC typically comes with lower write endurance than TLC, but WD helps offset that with its nCache 4.0 system. This acts as a fast buffer, writing data to a pseudo-SLC cache before transferring it to the main NAND, which helps large transfers run more smoothly and reduces slowdowns. Combined with the Gen4 interface, this setup enables the higher-capacity models to achieve sequential read speeds exceeding 7GB/s.

For power usage, WD rates the average read and write power at 3.8 watts for the 500GB model, 3.9 watts for the 1TB model, and 4.1 watts for the 2TB model. In idle sleep mode, it drops to just four milliwatts, making it a good fit for laptops. Endurance is rated at 300 TBW for the 500GB model, 600 TBW for the 1TB model, and 900 TBW for the 2TB model, along with a mean time to failure of 1.75 million hours. On the security side, the drive supports TCG Pyrite 2.01 and ATA Security passthrough over NVMe. It doesn’t offer full hardware encryption, but you still get a basic level of data protection if your system supports it.

WD includes Acronis True Image for SanDisk to facilitate data migration, along with the SanDisk Dashboard for firmware updates and health monitoring. You also get a five-year limited warranty, which gives some peace of mind when it comes to long-term reliability.

WD Blue SN5100 Pricing and Availability

Available now, the WD Blue SN5100 is currently priced at $55 (500GB), $80 (1TB), $150 (2TB), and $300 (4TB) at the time of this review. We will be looking at the 2TB model for this review.

WD Blue SN5100 Specifications

WD Blue SN5100 Performance

Before diving into the benchmarks, here’s a list of comparable Gen5 drives tested alongside the 2TB Sandisk SN5100, along with a few Gen4 SSDs:

• Phison E28 (Reference design)
• PNY CS2150
• Lexar Professional NM1090 PRO
• SK hynix Platinum P51
• Kingston FURY Renegade G5
• SanDisk WD_BLACK SN8100
• Crucial T705
• Crucial P510
• Crucial P310 (PCIe Gen4)
• Samsung 9100 Pro
• Samsung 990 Pro (PCIe Gen4)
• WD SN850X (PCIe Gen4)

We subjected these drives to various tests to evaluate their real-world and synthetic performance. This includes LLM load times to measure how quickly they handle large AI models, DirectStorage tests to assess how fast they load game assets and process in-game data, and BlackMagic Design tests to evaluate read and write speeds for high-resolution video editing. We’ll also run PCMark 10 to gauge overall system responsiveness, 3DMark Storage to test gaming performance, and FIGO tests to measure peak sequential and random read/write speeds under heavy workloads.

Here’s the high-performance test rig we used for benchmarking:

• CPU: AMD Ryzen 7 9800X3D
• Motherboard: Asus ROG Crosshair X870E Hero
• RAM: G.SKILL Trident Z5 Royal Series DDR5-6000 (2x16GB)
• GPU: NVIDIA GeForce RTX 4090
• OS: Windows 11 Pro, Ubuntu 24.10 Desktop

Peak Synthetic Performance

The FIO test is a flexible and powerful benchmarking tool used to measure the performance of storage devices, including SSDs and HDDs. It evaluates metrics such as bandwidth, IOPS (Input/Output Operations Per Second), and latency under different workloads, like sequential and random read/write operations. This test helps to assess the peak performance of storage systems, making it useful for comparing different devices or configurations. We measured the peak burst performance for this test, limiting the workload to a 10GB footprint on both SSDs.

When looking at the FIO data (and all other benchmarks), we are focusing on two of our most similar Gen4 drives, the WD SN5100 2TB and the Crucial P310 2TB. Here, they delivered nearly identical sequential results, with the WD slightly ahead in read (7,329MB/s vs. 7,197MB/s) and write (6,740MB/s vs. 6,376MB/s). The real divergence showed up in random operations: the P310’s 1.16M IOPS random read result gave it a big lead over the SN5100’s 415K IOPS, although it countered with a stronger 931K random write vs. the P310’s 1.19M. This makes the P310 a bit more consistent across workloads, while the SN5100 shows selective strength in sequential and write-heavy cases. Higher-tier TLC-based Gen4 and Gen5 drives far outpace both, but between these two QLC options, the matchup is close depending on the use case.

In other scores, the Samsung 990 Pro 2TB came in stronger at 7,483MB/s read, 7,197MB/s write, and 1.40M IOPS in both random read and write, showing why it remains one of the best-performing Gen4 SSDs. The WD SN850X 2TB delivered 6,632MB/s read, 7,235MB/s write, 1.20M IOPS random read, and 825K IOPS random write, offering a balance between sequential throughput and high random performance.

Average LLM Load Time

The Average LLM Load Time test evaluated the load times of three different LLMs: DeepSeek R1 7B, Meta Llama 3.2 11B, and DeepSeek R1 32B. Each model was tested 10 times, and the average load time was calculated. This test measures the drive’s ability to load large language models (LLMs) into memory quickly. LLM load times are crucial for AI-related tasks, particularly for real-time inference and processing large datasets. Faster loading enables the model to process data rapidly, thereby improving AI responsiveness and reducing waiting time.

When loading large language models, the WD SN5100 and Crucial P310 again tracked closely. The SN5100 finished DeepSeek R1 7B in 2.99s compared to the P310’s 3.19s, a small edge for WD on lighter models. With Meta Llama 11B and DeepSeek 32B, however, the Crucial drive pulled even or slightly ahead, clocking 3.71s and 5.48s, respectively, against the SN5100’s 3.67s and 5.58s. The gap is narrow enough that in day-to-day AI model loading, both offer a similar, value-driven experience, though neither approaches the lower latencies of top competitors, including Samsung’s flagship 990 Pro or the better-balanced SN850X.

3DMark Direct Storage

The 3DMark DirectStorage Feature Test evaluates how Microsoft’s DirectStorage optimizes game asset loading on PCIe SSDs. By reducing CPU overhead and improving data transfer speeds, DirectStorage enhances loading times, especially when paired with GDeflate compression and Windows 11’s BypassIO. This test isolates storage performance to highlight the potential bandwidth improvements when DirectStorage is enabled.

Here, the WD SN5100 2TB and Crucial P310 2TB landed in the same tier, but with different strengths. The SN5100 posted a higher compressed throughput at 15.22GB/s compared to the P310’s 14.81GB/s, and slightly stronger decompression bandwidth (65.61GB/s vs. 65.43GB/s). However, the P310 pulled ahead in uncompressed storage-to-VRAM transfers (8.56GB/s vs. the SN5100’s 5.83GB/s).

Compared to the upper tier of TLC-based Gen5 SSDs like the SK hynix Platinum P51 (26.32GB/s) and SanDisk SN8100 (26.11GB/s), the SN5100 is clearly outpaced, but that’s expected given its Gen4 QLC positioning. What the results highlight is that even on a more value-oriented platform, DirectStorage provides a measurable boost, helping the SN5100 deliver smoother game asset streaming and lower CPU overhead than older Gen4 designs; just not at the extreme levels reached by flagship Gen5 TLC drives.

BlackMagic Disk Speed Test

The BlackMagic Disk Speed Test benchmarks a drive’s read and write speeds, estimating its performance, especially for video editing tasks. It helps users ensure their storage is fast enough for high-resolution content, like 4K or 8K video.

The WD SN5100 and Crucial P310 landed neck-and-neck in BlackMagic results, which shows their shared QLC positioning. The SN5100 posted 5,395MB/s read and 5,866MB/s write, narrowly topping the P310’s 5,282MB/s read and 5,459MB/s write. This gives the WD a modest lead in sequential write-heavy workflows, while overall playback and editing pipelines will feel comparable on either drive. Neither matches the higher ceiling of TLC-based Gen4 models, but both handle 4K workloads capably.

Here’s our current BlackMagic disk speed leaderboard:

PCMark10 Storage

PCMark 10 Storage Benchmarks evaluate real-world storage performance using application-based traces. They test system and data drives, measuring bandwidth, access times, and consistency under load. These benchmarks offer practical insights beyond synthetic tests, enabling users to compare modern storage solutions effectively.

In application-level traces, the Crucial P310 2TB edged out the WD SN5100 2TB with a score of 6,436 vs. 6,379. The difference is small but consistent, suggesting Crucial’s controller and firmware tuning provide slightly more responsive day-to-day performance. Both sit in the midrange of the Gen4 lineup, well below Samsung’s 990 Pro at 7,173, yet clearly above older Gen4 designs like the SN850X (4,988). Between the two, Crucial takes a slight advantage in workloads that mirror real-world application usage. At the top of the chart, Gen5 drives like the Phison PS5028-E28 (9,347) and Crucial T705 (8,783) stretched well beyond what the Gen4 group can deliver.

3DMark Storage

The 3DMark Storage Benchmark tests your SSD’s gaming performance by measuring tasks like loading games, saving progress, installing game files, and recording gameplay. It evaluates how well your storage handles real-world gaming activities and supports the latest storage technologies for accurate performance insights.

For gaming-centric tasks, the WD SN5100 managed to pull ahead of the Crucial P310, scoring 4,192 against Crucial’s 3,848. This edge puts the WD closer to the mid-pack of Gen4 options, even surpassing Samsung’s 990 Pro (4,128) in this test. Game installs, loads, and recording workflows should feel a bit quicker on the SN5100 compared to the P310, though both remain limited compared to flagship Gen5 TLC drives. For gamers choosing between the two QLC Gen4s, the WD shows a more favorable profile.

Ultimately, for gaming workloads like installs, level loads, and recording, the SN5100 delivers respectable performance within its Gen4 class but does not reach the responsiveness offered by top Gen5 options.

GPU Direct Storage

One of the tests we conducted on this testbench was the Magnum IO GPU Direct Storage (GDS) test. GDS is a feature developed by NVIDIA that allows GPUs to bypass the CPU when accessing data stored on NVMe drives or other high-speed storage devices. Instead of routing data through the CPU and system memory, GDS enables direct communication between the GPU and the storage device, significantly reducing latency and improving data throughput.

How GPU Direct Storage Works

Traditionally, when a GPU processes data stored on an NVMe drive, the data must first travel through the CPU and system memory before reaching the GPU. This process introduces bottlenecks, as the CPU becomes a middleman, adding latency and consuming valuable system resources. GPU Direct Storage eliminates this inefficiency by enabling the GPU to access data directly from the storage device via the PCIe bus. This direct path reduces the overhead associated with data movement, allowing faster and more efficient data transfers.

AI workloads, especially those involving deep learning, are highly data-intensive. Training large neural networks requires processing terabytes of data, and any delay in data transfer can lead to underutilized GPUs and longer training times. GPU Direct Storage addresses this challenge by ensuring that data is delivered to the GPU as quickly as possible, minimizing idle time and maximizing computational efficiency.

In addition, GDS is particularly beneficial for workloads that involve streaming large datasets, such as video processing, natural language processing, or real-time inference. By reducing the reliance on the CPU, GDS accelerates data movement and frees up CPU resources for other tasks, further enhancing overall system performance.

Results

In the GDSIO tests we compare the lineup of QLC Gen4 drives, the WD SN5100 again went back and forth with the Crucial P310, but generally placed just ahead. At small 16K block sizes, both hovered in the low 2.3 GiB/s range, though the P310 edged WD slightly on write latency. As block sizes grew, the SN5100’s read and write throughput peaked at 3.8/3.6 GiB/s at 128K and 4.1/4.0 GiB/s at 1M, compared to the P310’s 4.1/3.9 GiB/s at 1M. This keeps the WD competitive, with slightly higher consistency in read-heavy runs. Against other Gen4 QLC and TLC drives, both the SN5100 and P310 are clearly budget-oriented, but the WD maintains a small overall lead.

Here’s a full run-down:

Conclusion

The WD Blue SN5100 isn’t built to compete with Gen5 SSDs, and that’s perfectly fine. In a test pool mostly filled with faster, more expensive drives, this Gen4 SSD still manages to hold its place for users who care more about overall value. Among the other Gen4 drives we tested, it landed behind the Samsung 990 Pro across the board, and also trailed the older WD SN850X in random workloads. Still, its sequential numbers were respectable, and it stayed consistent enough to be considered a viable option in this more budget-conscious space.

In real-world use, especially for productivity and creative workflows, the SN5100 should feel responsive and capable. It posted sequential results of over 7,300MB/s read and 6,700MB/s write at the 2TB capacity, which places it just ahead of Crucial’s P310 (7,197MB/s and 6,376MB/s). This positions both as competitive, budget-oriented Gen4 QLC options, with the SN5100 carrying a slight edge in straight sequential throughput. Random performance, however, told a different story. The Crucial drive delivered over 1.1M IOPS in 4K random reads compared to the SN5100’s 415K, with stronger 4K write performance (1.19M IOPS vs 931K) as well. Both fell short of premium TLC-based Gen4 models like the Samsung 990 Pro or SN850X, which scale much higher in mixed workloads. That said, outside of heavy, random, or prosumer-oriented scenarios, the differences are unlikely to be noticed day to day. For boot times, file transfers, and light creative tasks, both the SN5100 and P310 will deliver competent performance, with the WD favoring sequential operations thanks to its nCache system. Note, however, that the SN5100 is slightly pricier than the P310 as of this review.

Power efficiency does look good based on WD’s published specs. The SN5100’s rated active draw stays under 4.1 watts across capacities, and idle power drops to just 4 milliwatts, which should be helpful for battery-conscious laptop users. We didn’t validate these numbers in testing, but they make the SN5100 an appealing option for mobile or low-power builds. Endurance ratings are also reasonable for a QLC-based drive, with a five-year limited warranty for peace of mind.

In the end, the SN5100 simply fills a value-centric role in WD’s consumer SSD lineup. If you’re running a Gen4 system and want a solid storage solution that prioritizes price over top-class speeds or just a dependable drive for a secondary slot or laptop upgrade, this drive gets the job done.

SanDisk WD SN5100 Product Page

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