With the P31, Hynix has entered the enthusiast SSD space with a truly impressive drive that unfortunately was only available in a 512 GB and 1 TB variant until now. Enthusiasts demanded more storage, Hynix listened, and we're reviewing the 2 TB Hynix Gold P31 today. Under the hood, the P31 uses only in-house components—everything is manufactured by Hynix. Previously, only Samsung had this ability, which not only helped with engineering a good product, but is also more cost efficient. I don't know if Hynix plans to sell their controller to third parties or whether they will keep it in-house only. Selling the controller would definitely shake up things in the SSD space, which is currently dominated by Silicon Motion and Phison.

Synthetic numbers of the Hynix Gold P31 are very impressive. Random IO, mixed, read, and write are right up there, battling it out with the best PCIe Gen 3 drives in our test group. The P31 "only" supports the PCIe Gen 3 interface, but is also more affordable than the newest Gen 4 flagships, which offer much higher sequential transfer rates. While vendors only want you to look at the sequential speeds, these merely play a small role in real-life performance; random IO is more important for most workloads. Interesting to see is that the reviewed 2 TB version has exactly the same synthetic performance results as the 1 TB version we reviewed a while ago.

When we look at real-life numbers, things are slightly different—performance of the 2 TB version is slightly slower than the 1 TB version. With 1%, the difference is minimal though, pretty much insignificant when considering daily usage. I suspect the difference is due to our real-life testing happening at 80% drive full capacity, which puts additional stress on the controller, SLC cache, and DRAM mapping table algorithms. Nevertheless, the Hynix Gold P31 2 TB achieves amazing performance that's better than all the PCI-Express Gen 3 drives we've ever reviewed. The only exception here is the Samsung 980 non-Pro, which matches the Hynix Gold P31's performance. It beats famous drives like the HP EX950 by 2%, ADATA SX8200 Pro by 1%, and Kingston KC2000 by 2%. PCIe 4.0 drives with less powerful controllers, like the ADATA S70 and Gigabyte AORUS Gen 4, do fall behind the P31 despite their faster interface. Only the fastest Gen 4 SSDs can beat the Hynix P31: the Corsair MP600 Pro by 2%, Samsung 980 Pro 4%, and WD Black SN850 4%. These are tiny differences that make it very hard to justify the price increase. On the other hand, if the majority of your workloads are sequential transfers, going PCIe Gen 4 can definitely make sense.

Sequential write performance of the Hynix Gold P31 is excellent, better than most competing drives. Filling the whole 2 TB capacity completed at 1.4 GB/s, which is one of the best PCIe Gen 3 TLC SSD results we ever saw. With 166 GB, the pseudo-SLC cache is reasonably large, sufficient for nearly all workloads, though I still would have wished for a bit more. SLC cache usually operates as a percentage of the drive's free space, so as the drive fills up, SLC cache size goes down slowly. That's why I feel an SLC cache of around 250 GB (on an empty 1 TB drive) would have been slightly better. Once again, we're testing our real-life benchmarks at 80% disk full, so the SLC cache size is already taken into account for our real-life performance results, which are impressive. Of course, momentarily stopping the write activity will have the SLC cache free up capacity immediately, so full write rates are available as soon as you give the drive a moment to settle down.

Unlike some other high-end M.2 NVMe SSDs, the Hynix Gold P31 does not come with a heatsink preinstalled, and it doesn't need one. Even in our worst-case thermal loading test did we not even see a hint of thermal throttling—very impressive. This clearly sets the drive apart from Phison and SMI-powered drives, which do run into thermal throttling in some situations. The magic lies in the controller, which must be a very energy-efficient design—lower energy consumption means less heat output, which avoids throttling.

Hynix started listing the P31 2 TB last week, at a price point of $280, with a $15 discount available on Amazon. At $265, the P31 is an excellent choice if you're looking for an affordable high-performance M.2 NVMe SSD. The performance offered is very close to PCIe Gen 4 drives, which are much more expensive; Samsung 980 Pro: $342, WD Black SN850: $360, Corsair MP600 Pro: $365, Crucial P5 Plus: $370. Some leading PCIe Gen 3 drives are competitive with the P31, though. For example, the ADATA SX8200 Pro is $220, Kingston KC2500 $277, and HP EX950 $283. Taking into account the $15 discount, I'd still pick the P31 over all these choices. If you only care about price/performance and are happy to sacrifice some performance for better pricing, entry-level value M.2 NVMe SSDs could be an option; these retail at around $200 and below and are not that much slower.