Sequential Read Performance

Our first test of sequential read performance uses short bursts of 128MB, issued as 128kB operations with no queuing. The test averages performance across eight bursts for a total of 1GB of data transferred from a drive containing 16GB of data. Between each burst the drive is given enough idle time to keep the overall duty cycle at 20%.

Burst 128kB Sequential Read (Queue Depth 1)

The burst sequential read performance from the SK hynix Gold P31 is very good, but not quite fast enough to beat the drives based on the Silicon Motion SM2262EN controller.

Our test of sustained sequential reads uses queue depths from 1 to 32, with the performance and power scores computed as the average of QD1, QD2 and QD4. Each queue depth is tested for up to one minute or 32GB transferred, from a drive containing 64GB of data. This test is run twice: once with the drive prepared by sequentially writing the test data, and again after the random write test has mixed things up, causing fragmentation inside the SSD that isn't visible to the OS. These two scores represent the two extremes of how the drive would perform under real-world usage, where wear leveling and modifications to some existing data will create some internal fragmentation that degrades performance, but usually not to the extent shown here.

Sustained 128kB Sequential Read

On the longer sequential read test that involves some slightly higher queue depths, the Gold P31 is basically tied for first place when reading data that was written sequentially. When reading data that has previously been fragmented by the random write test, the P31's performance is considerably higher than the other flash-based SSDs and closer to the Optane 905P.

Sustained 128kB Sequential Read (Power Efficiency)
Power Efficiency in MB/s/W Average Power in W

In absolute terms, the power consumption of the Gold P31 isn't drastically lower than some of the other fairly efficient high-end NVMe drives like the WD Black SN750. But once performance is taken into account, the Gold P31's efficiency stands far above the competition.

The SK hynix Gold P31 doesn't need high queue depths to deliver good sequential read throughput: at QD2 it's already above 3 GB/s, but there are further slight performance increases from higher queue depths. That performance profile is very similar to the Samsung 970 EVO Plus, but that drive requires about twice the power that the P31 uses.

Even at QD1, the sequential read performance from the Gold P31 is above the ~2GB/s limit of most other four-channel NVMe drives we've tested (with eg. Silicon Motion SM2263 based controllers). That leaves it entirely in a performance range where all the competitors are 8-channel drives that don't come close to matching power efficiency of the Gold P31.

Sequential Write Performance

Our test of sequential write burst performance is structured identically to the sequential read burst performance test save for the direction of the data transfer. Each burst writes 128MB as 128kB operations issued at QD1, for a total of 1GB of data written to a drive containing 16GB of data.

Burst 128kB Sequential Write (Queue Depth 1)

The SK hynix Gold P31 has fairly ordinary burst sequential write performance by high-end NVMe standards: tied with the SM2262EN-based ATATA SX8200 Pro but beat by the Phison-based Seagate drives.

Our test of sustained sequential writes is structured identically to our sustained sequential read test, save for the direction of the data transfers. Queue depths range from 1 to 32 and each queue depth is tested for up to one minute or 32GB, followed by up to one minute of idle time for the drive to cool off and perform garbage collection. The test is confined to a 64GB span of the drive.

Sustained 128kB Sequential Write

On the longer sequential write test that brings in higher queue depths, the Gold P31 is tied for second place, while the Phison E16 based Seagate drive (built for PCIe 4 speeds, but limited by this testbed to PCIe 3 speeds) unsurprisingly takes first place.

Sustained 128kB Sequential Write (Power Efficiency)
Power Efficiency in MB/s/W Average Power in W

At this point, the record-shattering power efficiency scores from the SK hynix Gold P31 are no longer a surprise. The overall fastest drive has the second best efficiency score (56% the performance per Watt of the P31) and the next two most efficient drives are much slower NVMe drives from Toshiba/Kioxia.

The Gold P31 doesn't reach its full sequential write speed until QD4, while several of its competitors saturate at QD2. However, once the P31 is at full speed, it has one of the best sustained write speeds, and shows no sign of its SLC cache running out at any point during the test. Power consumption is comparable to the slowest NVMe drive that can barely hit half the throughput of the Gold P31.

Similar to the sequential read results, the P31 starts out at QD1 with high performance that almost puts it beyond what other 4-channel NVMe drives can do at any queue depth. From there, the P31 continues to redefine what's possible with an increasingly wide lead in power consumption relative to all other high-end drives we've tested.

Random Performance Mixed Read/Write Performance
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  • ballsystemlord - Thursday, August 27, 2020 - link

    @Billy Thanks for the review. There have been several new SSD releases this year. I look forward to more SSD articles!
  • ballsystemlord - Thursday, August 27, 2020 - link

    Of course, I'm assuming manufacturers are sampling you guys. (:
  • serendip - Thursday, August 27, 2020 - link

    There needs to be more options for 2230 and 2242 drives. More laptops are coming out with replaceable drives in those smaller form factors.
  • Samus - Friday, August 28, 2020 - link

    Kinda feel stupid for buying an SN750 a few weeks ago...
  • vladx - Friday, August 28, 2020 - link

    Still an excellent drive, a bit pricey though...
  • cfbcfb - Sunday, August 30, 2020 - link

    Just installed one in my desktop t replace an older Hynix OEM 256GB drive.

    Zero issues cloning, I used Macrium to "backup everything needed for windows" to another drive, made a usb stick with standalone macrium, put in the p31 and booted from the usb, restored the image and I was off and running.

    Stunning speed for the price, especially the write speed. In some instances I'm seeing faster writes than reads. And hey, power savings and less heat from a non heatsink nvme drive is okay in a desktop too! That's one of the reasons why I got it. With most other high end drives you need a heatsink unless you have a fan blowing on it, and in my system the m.2 slot is right next to the gpu in the only x16 slot, and the nearest fan is the cpu heatsink fan.

    So my old drive would often hit 60-80c. No bueno. This one? After hammering it, its still barely warmer than ambient case temp. Plus its one sided, which is nice.

    A WD 750 black with heatsink or an 8200 pro with heatsink are MUCH more expensive.

    This is a MSRP deal of the year for nvme high end drives. Durability and warranty are also excellent.

    So its not just for laptops. Don't hesitate to buy this drive if you want a high end nvme SSD in ANY device.
  • nfriedly - Monday, August 31, 2020 - link

    Is the Gold P31 a single-sided drive or a double-sided drive? (In other words does it have any components on the bottom?) There are a few smaller laptops, such as the GPD Win Max, that only have room for single-sided drives.
  • Srikzquest - Wednesday, October 14, 2020 - link

    This one is a single sided drive, that's a plus against ADATA's XPG 8200 Pro.
  • AnarchoPrimitiv - Monday, August 31, 2020 - link

    I'll hold back on calling it a "fantastic laptop drive" until it's actually put in a laptop with battery duration tests performed and compared to other drives. If it's power savings only equate to 15 extra minutes of battery in real life for example, then it's definitely not worth the compromise on performances.
  • Srikzquest - Wednesday, October 14, 2020 - link

    That's the point, there is hardly any compromise with performance. Its equally good on Efficiency and Performance.

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