WD Blue SN5000 4TB SSD review: Western Digital launches a 4TB mainstream drive

Comparison Products and Testing

For comparison today we’re going to have a little bit of everything. We have the PCIe 3.0 WD Red SN700 and extend all the way to the PCIe 5.0 Crucial T700, with a collection of other SSDs in between. The Samsung 990 Pro 4TB rates as the top 4TB drive we've tested, and we have popular budget like the Lexar NM790 and Addlink A93. Older drives with DRAM include the Sabrent Rocket 4 Plus-G, the Seagate FireCuda 530, and the Netac NV7000. Lastly, we have a mid-range 4.0 drive with QLC flash in the Sabrent Rocket Q4, a drive that the SN5000 should fully supplant.

Trace Testing — 3DMark Storage Benchmark

Built for gamers, 3DMark’s Storage Benchmark focuses on real-world gaming performance. Each round in this benchmark stresses storage based on gaming activities including loading games, saving progress, installing game files, and recording gameplay video streams. Future gaming benchmarks will be DirectStorage-inclusive and we include details of that where possible.

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The SN5000 performs surprisingly well in 3DMark, technically landing in the middle of the pack of 4TB drives on the chart, but it's not that far off drives like the 990 Pro. This is a good thing, as this drive is a potential candidate for a dedicated games drive, especially at 4TB. At lower capacities it should perform similarly, given that it’s essentially a cousin of the SN580 and SN770. For 4TB, it just needs to be priced right, as you can get TLC-based drives like the NM790 at often a surprisingly low price.

We may eventually see more QLC-based options like the HP FX700 that are more of a direct threat, but otherwise the SN5000 competes with the Crucial P3 Plus and Corsair MP600 Core XT. If you've been considering those drives for capacity on the cheap, the SN5000 potentially offers an alternative with a mature controller design. 

Trace Testing — PCMark 10 Storage Benchmark

PCMark 10 is a trace-based benchmark that uses a wide-ranging set of real-world traces from popular applications and everyday tasks to measure the performance of storage devices.

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The SN5000 does even better in PCMark 10, still falling behind the 990 Pro but coming out ahead of solid performers like the NM790 and A93. QLC flash has its downsides, but the typical user experience with this drive should be good. Problems arise when the drive gets fuller or after a prolonged workload. Looking at the ISSCC numbers for this flash, though, it’s comparable to early generations of 3D TLC flash, which when bolstered by a large pSLC cache means the SN5000 can feel fairly responsive in daily driving.

Console Testing — PlayStation 5 Transfers 

The PlayStation 5 is capable of taking one additional PCIe 4.0 or faster SSD for extra game storage, with some requirements. The PS5 now supports up to 8TB drives, and while any 4.0 drive will work, Sony specifies drives that can deliver at least 5,500 MB/s of sequential read bandwidth are optimal. The PS5 does not support the host memory buffer (HMB) feature but DRAM-less drives still work. In our testing, PCIe 5.0 SSDs don't bring much to the table and generally should not be used in the PS5, especially as they may require additional cooling. Please see our Best PS5 SSDs article for more information.

Our testing utilizes the PS5’s internal storage test and manual read/write tests with over 192GB of data both from and to the internal storage. Throttling is prevented where possible using a Sabrent PS5 heatsink to see how each drive operates under ideal conditions.

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The PlayStation 5 does not require anything special for an extra SSD, although ideally you should hit the 5.5 GB/s mark or higher. The 4TB SN5000 can do this and it provides essentially the same load time performance as faster drives. It’s a suitable alternative to drives like the A93 and NM790 if you want 4TB, but to make sense it needs to be less expensive.

Transfer Rates — DiskBench

We use the DiskBench storage benchmarking tool to test file transfer performance with a custom, 50GB dataset. We write 31,227 files of various types, such as pictures, PDFs, and videos to the test drive, then make a copy of that data to a new folder, and follow up with a reading test of a newly-written 6.5GB zip file. This is a real world type workload that fits into the cache of most drives.

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DiskBench gives a good picture of how real world file transfers fare on the SSDs. Copy performance is generally limited by the write speed, which will be lower than the read speed. For the most part, data will fit into the pSLC cache, so you can get good performance from most drives. This is the case here, with the SN5000 effectively matching “faster” drives, especially as copying is at a low queue depth.

Synthetic Testing — ATTO / CrystalDiskMark

ATTO and CrystalDiskMark (CDM) are free and easy-to-use storage benchmarking tools that SSD vendors commonly use to assign performance specifications to their products. Both of these tools give us insight into how each device handles different file sizes and at different queue depths. For ATTO, we show both linear and logarithmic scaling on the Y-axis, with the latter showing more differentiation at low queue depths.

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The SN5000 performs as expected in ATTO, with an upward curve and a peak around 512KiB, more noticeable with reads. This matches our findings with the WD Blue SN580 quite well, though the drive is unable to reach the heights of SDDS that can push more bandwidth. Sequential performance is likewise limited in CDM, although QD1 reads are surprisingly good. To some extent this can translate to faster game and application load times, although generally any gaps there are small.

Random performance, in particular low queue depth random 4KB reads, is quite good. Random write latency is relatively low against even newer drives while the drive’s read latency is the best in the lineup. Data at rest will perform well on this drive, making it a good option for static data. If you’re looking for a game drive, this would fit the bill.

Sustained Write Performance and Cache Recovery

Official write specifications are only part of the performance picture. Most SSDs implement a write cache, which is a fast area of (usually) pseudo-SLC programmed flash that absorbs incoming data.  Sustained write speeds can suffer tremendously once the workload spills outside of the cache and into the "native" TLC or QLC flash.

We use Iometer to hammer the SSD with sequential writes for over 15 minutes to measure both the size of the write cache and performance after the cache is saturated. We also monitor cache recovery via multiple idle rounds. This process shows the performance of the drive in various states as well as the steady state write performance.

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The SN5000 uses WD’s — or SanDisk’s if you prefer — nCache 4.0 technology, which is a hybrid cache that runs almost the full extent of the drive. This is similar to the Blue SN580, Black SN770M, and WD Black SN850X. Such a cache is part static and part dynamic, offering better consistency than one would otherwise expect. The result is that the SN5000 writes at almost 5 GB/s in pSLC mode before hitting a pseudo-folding state at around 544 MB/s. This is far superior to the post-cache performance of other QLC-based drives like the Crucial P3 Plus.

What’s most likely happening is that the SN5000 is alternating between direct-to-QLC and folding. If the drive is left idle, it goes back to the former performance state. Eventually it will recover pSLC, but the native QLC flash speed is good enough to pull up steady state performance. Above, we compared this QLC flash to early generation TLC flash, and this is where that becomes more apparent. According to the ISSCC documents, this flash could reach up to 60 MB/s per die. To put that into context, that’s more than twice as fast as Micron’s 176-Layer QLC flash used on the P3 Plus.

The caching scheme here, in comparison to Crucial’s full-drive dynamic, enables much higher steady state write performance. Considering that the cache is still fairly large, this is a good result and a good compromise, and certainly reminiscent of some older PCIe 3.0 TLC-based SSDs. Peak performance is higher than what was possible with 3.0, but also falls behind the faster PCIe 4.0 drives. While this doesn’t seem exciting on the surface, it means you can potentially get a robust gaming drive at up to 4TB without breaking the bank or having to suffer the P3 Plus’s questionable full-drive performance. It also means that QLC flash has, in a way, caught up to baseline TLC flash performance.

Power Consumption and Temperature

We use the Quarch HD Programmable Power Module to gain a deeper understanding of power characteristics. Idle power consumption is an important aspect to consider, especially if you're looking for a laptop upgrade as even the best ultrabooks can have mediocre stock storage. Desktops may be more performance-oriented with less support for power-saving features, so we show the worst-case.

Some SSDs can consume watts of power at idle while better-suited ones sip just milliwatts. Average workload power consumption and max consumption are two other aspects of power consumption but performance-per-watt, or efficiency, is more important. A drive might consume more power during any given workload, but accomplishing a task faster allows the drive to drop into an idle state more quickly, ultimately saving energy.

For temperature recording we currently poll the drive’s primary composite sensor during testing with a 21-22°C ambient. Our testing is rigorous enough to heat the drive to a realistic ceiling temperature for a well-ventilated case. Systems without a heatsink or sufficient airflow will see higher temperatures that what we show.

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In order for the SN5000 to be a slam dunk, it needs to be power-efficient and cool-running so that it can compete as a laptop option. It does this quite admirably, being efficient though not quite topping the charts. It’s pretty close to the Corsair MP600 Elite, which uses Phison’s E27T controller with TLC flash, and is ahead of the Crucial T500 that has DRAM. It would certainly work well in any laptop. The drive only pulled a maximum of 4.73W for us, although it is rated by SMART for up to 6.3W. This is a good result.

The SN5000 hit a maximum temperature of 73°C, which isn’t bad considering how long it can write at maximum speed. The first throttling state, as given by SMART, is at 90°C, giving a decent amount of headroom. This drive should not require additional cooling in normal use but would not be difficult to cool if that’s an option.

Test Bench and Testing Notes

We use an Alder Lake platform with most background applications such as indexing, Windows updates, and anti-virus disabled in the OS to reduce run-to-run variability. Each SSD is prefilled to 50% capacity and tested as a secondary device. Unless noted, we use active cooling for all SSDs.

WD Blue SN5000 Bottom Line 

The WD Blue SN5000 SSD punches above its weight. Its QLC flash is the best we've ever seen, and its pSLC performance, buoyed by WD’s hybrid cache design, is quite good. Performance ends up being solid and consistent everywhere it matters. The drive is also single-sided, power-efficient, and relatively cool-running. WD also backs it with useful software and a reasonable warranty. Our primary complaint ends up being cost: Will this 4TB become competitively priced, and how long before that happens?

Another thing worth mentioning is that our review sample is 4TB and it’s not surprising WD sent out 4TB drives to reviewers without too much fanfare. It’s the only SKU to offer something new. At lower capacities, you’d be forgiven for thinking this is an SN770 in a blue package, because that’s basically the reality. That older hardware remains quite capable, but increased competition means those smaller capacity drives have to be priced aggressively. The 4TB capacity point is more interesting, even if the SN5000 doesn’t quite push the limits of its PCIe 4.0 interface.

The 4TB Blue SN5000’s primary competition consists of a variety of options. The Crucial P3 and P3 Plus, Corsair MP600 Core XT, Silicon Power UD90, and other drives that reach 4TB with QLC flash at 5 GB/s or so all land in the same general ballpark. Against these the SN5000 seems like an easy choice. Its flash is faster, it’s single-sided and efficient, and the controller technology is proven. It also stands up well to older PCIe 3.0 designs, like the now-vanished Team MP34 4TB, as it runs cooler and should be more reliable. It also gives the newer Samsung 990 EVO a run for its money. All it really has to do is come down in price.

Against faster PCIe 4.0 SSDs, the SN5000 falls behind. It won’t match the TLC-based NM790, A93, Team MP44, or Patriot Viper VP4300 Lite, and it’s also technically no match for older DRAM-equipped drives like the Adata Legend 960 Max, Silicon Power XS70, or Sabrent Rocket 4 Plus/Plus-G. However, the SN5000 is more efficient than the latter pack and could be a good alternative to the former SSDs if it’s priced competitively.

The Silicon Power US75 4TB, which has the same Maxio MAP1602 controller and YMTC 232-layer TLC NAND as the A93 and NM790, currently costs $219 by way of comparison. Considering that overall performance tends to favor those drives as well as the Netac NV7000, the WD Blue SN5000 4TB needs to at least match those on pricing if it's to be viable.

Overall, the SN5000 4TB is plenty fast for a laptop or PS5, or as a secondary drive for an enthusiast desktop build, and for the most part it punches above its weight. Even when it doesn’t, it beats other QLC-based drives on the market. So it really comes down to value. WD has to price the 4TB WD Blue SN5000 accordingly. It currently costs $349 on Amazon, though direct from WD you can get it for $279. A bit lower and it will become a much more reasonable upgrade option. Hopefully that happens sooner than later.

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