Whole-Drive Fill

This test starts with a freshly-erased drive and fills it with 128kB sequential writes at queue depth 32, recording the write speed for each 1GB segment. This test is not representative of any ordinary client/consumer usage pattern, but it does allow us to observe transitions in the drive's behavior as it fills up. This can allow us to estimate the size of any SLC write cache, and get a sense for how much performance remains on the rare occasions where real-world usage keeps writing data after filling the cache.

The SLC write cache in the 1TB SK hynix Gold P31 runs out after just over 100GB of writes. After the SLC cache fills up, the Gold P31's sequential write performance becomes highly variable, ranging from about 1.4 to 2.3 GB/s with little change in character across the entire TLC filling phase. There are no obvious patterns of periodic garbage collection cycles visible at this scale.

Sustained 128kB Sequential Write (Power Efficiency)
Average Throughput for last 16 GB Overall Average Throughput

Despite the variability, the P31's long-term sustained write performance is excellent. It averages out to the best overall write throughput we've measured from a 1TB TLC drive, and in all that variation the performance never drops down to a disappointing level.

Working Set Size

Most mainstream SSDs have enough DRAM to store the entire mapping table that translates logical block addresses into physical flash memory addresses. DRAMless drives only have small buffers to cache a portion of this mapping information. Some NVMe SSDs support the Host Memory Buffer feature and can borrow a piece of the host system's DRAM for this cache rather needing lots of on-controller memory.

When accessing a logical block whose mapping is not cached, the drive needs to read the mapping from the full table stored on the flash memory before it can read the user data stored at that logical block. This adds extra latency to read operations and in the worst case may double random read latency.

We can see the effects of the size of any mapping buffer by performing random reads from different sized portions of the drive. When performing random reads from a small slice of the drive, we expect the mappings to all fit in the cache, and when performing random reads from the entire drive, we expect mostly cache misses.

When performing this test on mainstream drives with a full-sized DRAM cache, we expect performance to be generally constant regardless of the working set size, or for performance to drop only slightly as the working set size increases.

As expected for a drive with a full size DRAM buffer, the P31's random read latency is unaffected by spatial locality: reading across the whole drive is just as fast as reading from a narrow range. And the only other TLC drives that can match this read latency are the two Toshiba/Kioxia SSDs with 96L BiCS4 TLC NAND, but they can't maintain this performance across the entire test.

SK hynix Gold P31 1TB Review AnandTech Storage Bench
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  • jaydee - Tuesday, September 1, 2020 - link

    Thanks Billy! Reading the part about the power efficiency though, any thoughts of quantifying the extra battery life you could expect to see (typical laptop) from the SK Hynix Gold P31 over a Phison E12? The numbers look impressive on paper in terms of percentages against other HDs, but what are we talking about? An extra.. 5/10/15/20 minutes under an extreme R/W heavy workload? What about an average R/W workload? For sure the price/performance is there too so it appears a good buy anyway, I just don't know what to make of the efficiency numbers in terms of actual computing experience.
  • Jimster480 - Saturday, September 5, 2020 - link

    I just put this into my new Ryzen 4600H Powered Nitro 5 and it beats my EX920 in everything! Really a leap in performance and power consumption that wasn't expected from SK Hynix that has been an Also-ran until now!
  • rlr297 - Wednesday, September 23, 2020 - link

    Is there an update on when the platinum drives will be released? I am looking for a 2TB variant. If not, do you have a 2TB drive you'd recommend for a laptop?
  • MatthiasM - Tuesday, November 10, 2020 - link

    Hi All: Can I please ask for collective wisdom? I was very impressed by the review of this drive, especially the low power consumption for laptops. So, I bought one for my 2017 MacBook Air. This can use NVME drive with a Sintech Adapter, no problem. Several other NVME drive (WD, ADTA) run without problems. But when I built in this SK Hynix drive, it wouldn't start. It initiates the boot process, but won't complete it. But when I insert the drive in an external enclosure, it starts from it as boot drive, no problem. Only when it is internal, it won't start. Any suggestions? NVME controller incompatible with MacBook? Any ideas on how to fix this?
  • oRAirwolf - Monday, November 30, 2020 - link

    A little late to the fold, but there was a comment about drive software and firmware updates. SK Hynix released a tool for this drive called Drive Manager: Easy Kit. It's available at the very bottom of this page: https://ssd.skhynix.com/GoldP31.html
  • EarFull - Sunday, February 7, 2021 - link

    Totally over my head, I bought one of these off Amazon after finding out Hynix supplies OEM SSD's for Apple laptops. Thought I'd play with it as a peripheral plug in. Problem is, I can't find an external enclosure that is appropriate for it. I wrote Hynix and they commented it is only for INTERNAL use. Does anyone KNOW of an external enclosure suitable for this 1TB Hynix P31 Gold Drive? I don't care now if it is USB or Thunderbolt. Thank you.
  • EarFull - Sunday, February 7, 2021 - link

    Tried the Hynix P31 Gold NVME in the OWC Envoy Express: did not work. Now OWC site states in this configuration only available for Windows 10. Bummer.
  • EarFull - Thursday, February 11, 2021 - link

    Posted a comment two days ago and can't find it. To reiterate: bought Hynix P31Gold NVME to use as external drive. OWC Envoy Express will NOT work in this configuration on macOS. So, bought this SSK Aluminum M.2 NVME SSD Enclosure Adapter, USB 3.1 Gen 2 (10 Gbps) to NVME PCI-E M-Key Solid State Drive External Enclosure (Fits only NVMe PCIe 2242/2260/2280) to try. Indeed, it works perfectly for about $20. The enclosure is well made, metal, and comes with extra NVME 'screws' and such and two cabes for USB-C to USB-C as well as USB-C to USB-A. Hope this helps. Patrick
  • Davidm771 - Friday, November 26, 2021 - link

    Anyone know how the P31 Gold compares in terms of power efficiency against an SN730 OEM nvme drive? Read the specs of the SN730 and the power states are really low mostly except the PS1+2 numbers are better on the P31 Gold. Thanks
  • srahman5317 - Friday, January 21, 2022 - link

    Thank you so much guys. This was perfect and exactly the kind of reporting I was looking for. Much love from a laptop user

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