Burst IO Performance

Our burst IO tests run at a queue depth of one and the amount of data transferred is limited to ensure that SLC write buffers don't fill up and controllers don't overheat. In between each burst there's enough idle time to keep the drive averaging a 20% duty cycle, allowing for some buffered writes and deferred garbage collection to be completed. The random read and write tests use 4kB operations and the sequential tests use 128kB operations. All the burst tests are confined to a 16GB portion of the drive, so DRAMless SSDs are not disadvantaged as much as they are for larger tests.

QD1 Burst IO Performance
Random Read Random Write
Sequential Read Sequential Write

The aggressive SLC caching strategy used by the Corsair MP400 and most other QLC NVMe SSDs allows them to provide best-case random IO performance that is competitive with many high-end PCIe 3.0 drives. However, despite the 8-channel controller, the burst sequential IO performance of the Corsiar MP400 is still fairly low by NVMe standards. The Sabrent Rocket Q 8TB's results indicate that at least some of the higher-capacity MP400 models should also be able to provide better burst sequential write speeds by virtue of having larger and faster SLC caches.

Sustained IO Performance

Our sustained IO tests measure performance on queue depths up to 32, but the scores reported here are only the averages for the low queue depths (1,2,4) that are most representative of real-world consumer workloads. Each queue depth is tested for up to one minute or 32GB, and the tests are confined to a 64GB span of the drive.

Sustained IO Performance
Random Read Random Write
Sequential Read Sequential Write

On the longer synthetic IO tests, the Corsair MP400's best results are for random writes, where its SLC cache is sufficient to keep it competitive against high-end PCIe 3 drives. The sequential write and random read performance scores are both constrained to the entry-level NVMe performance ranges, but are competitive for that market segment. The sequential read performance is relatively poor even for entry-level NVMe drives, though still significantly better than Samsung's QLC SATA alternative.

Sustained IO Performance
Random Read Random Write
Sequential Read Sequential Write

With QLC NAND and an aging 8-channel controller, it's no surprise that the Corsair MP400's power efficiency scores are generally unimpressive, especially compared to what the 4-channel NVMe drives score when they are performing well. However, the only particularly poor efficiency score from the MP400 is for the sequential read test that it did not perform well on.

Performance at a glance
Random Read Random Write
Sequential Read Sequential Write

Plotting power and performance against our entire library of benchmark results shows that—for better or for worse—the Corsair MP400 doesn't stand out from the crowd or break new ground. The random read performance stays entirely within the range of SATA drives. Random and sequential writes make some use of PCIe performance, but don't come close to saturating the PCIe 3 x4 interface. The sequential read performance does almost make it to 3GB/s at higher queue depths, but it isn't able to fully saturate the PCIe interface the way the 8TB Sabrent Rocket Q can.

Random Read
Random Write
Sequential Read
Sequential Write

Digging into how performance and power scale with increasing queue depths reveals no particular surprises for the Corsair MP400. The biggest discrepancies with the 8TB Sabrent Rocket Q are for random reads and sequential writes: more flash allows the 8TB drive to continue scaling up random read performance after the 1TB MP400 is starting to reach saturation, and the larger SLC cache for the 8TB drive allows higher and more consistent sequential write performance.

AnandTech Storage Bench Mixed Read/Write Performance And Power Management
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  • Spunjji - Monday, December 14, 2020 - link

    That's a good point. Locking off 50GB a 2TB drive's capacity isn't a huge penalty to pay for the reward of having a guaranteed ~12.5GB of SLC cache available at all times, even with a "full" drive.
  • kavanoz - Saturday, December 12, 2020 - link

    When will Anandtech review Western Digital Black SN850?
  • Samus - Sunday, December 13, 2020 - link

    If you are getting a 1TB PCIe 3.0 SSD it'd be ridiculous not to get the P31, I replaced my WD SN750 that was chronically overheating and throttling in my system (65C-70C!) and the Hynix barely cracks 50C AND its faster. $110 shipped on Amazon.
  • Oxford Guy - Monday, December 14, 2020 - link

    Remember... if the drive doesn't fail spectacularly then it just has to be good quality.

    Speaking of "tropes"...

    Paying more than one should for inferior technology is not a problem at all. As long as the drive doesn't kick the bucket then it's all good.
  • Snowleopard3000 - Thursday, December 17, 2020 - link

    Does anyone know where to get 15x15x2mm Soft Silicone Thermal Conductive Pads for the M.2 drives, I am specifically looking for 2mm thick ones.

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