The SK Hynix Gold P31 (starts at $122 for 500GB; $225 for the 1TB version tested) is an internal SSD geared to gamers, designers, and content creators. It did well in our testing, showing surprising speed in benchmark tests that gauge a drive’s ability to boot an operating system or launch applications or games. It’s also rated as durable, indicated by a high terabytes written (TBW) spec that suggests a long lifetime before its cells begin to fail. Business-laptop upgraders and other security-conscious folks will want to look elsewhere due to its lack of 256-bit AES hardware-based encryption, and its sparse software set is limited to a migration/clone utility. But if you are looking for a price-aggressive SSD to host your games, graphics programs, or OS, it’s well worth it for its aptitude in quickly opening programs.
The Biggest Chip Maker You’ve Never Heard Of
You may not have heard of South Korea-based SK Hynix, but you have almost certainly benefited from its products, working for you stealthily behind the scenes. The 38-year-old company is the world’s second-largest maker of memory chips (after Samsung), and its DRAM and flash memory are found beneath the hoods of any number of prebuilt PCs, as well as in many SSDs. It only recently started selling its own branded SSDs, launching its first retail effort—the SK Hynix Gold S31, a 2.5-inch SATA SSD—in 2019. The Gold designation pegs a drive as one of the company’s mainstream products; higher-end products receive a Platinum moniker.
The Gold P31 employs the NVMe protocol over its four-lane PCI Express 3.0 bus. SK Hynix has touted it as the first 128-layer triple-level-cell (TLC) NAND flash-based SSD. It’s available in just the 1TB and 500GB capacities. (If you’re baffled by some of these terms, check out our SSD dejargonizer.)
SK Hynix rates the Gold P31 for sequential-read speeds of up to 3,500MBps for both capacities, and a write speed of up to 3,200MBps for the 1TB version, and up to 3,100MBps for the 500GB model. The drive uses SK Hynix’s Hyperwrite technology to maximize sequential-write speeds using an single-layer-cell (SLC) buffer.
The Gold P31 is designed to the Type-2280 M.2 form factor (which means it’s 80mm long), roughly the size and shape of a stick of gum. It measures 0.1 by 0.9 by 3.2 inches (HWD) and weighs 1.9 ounces. It should fit in any desktop motherboard slots that support M.2 PCI Express drives of its length, and many M.2-capable laptops, as well. But make sure that your laptop’s slot is long enough to take it. Lacking a heat spreader and with chips on just one side, it is very thin, but some laptop M.2 slots are limited to Type-2242 or Type-2260 drives (42mm or 60mm long, respectively).
Software and Security
The Gold P31’s supporting software is sparse, limited to a migration utility (developed in partnership with Macrium), which lets you clone a system disk to the drive. Business travelers, and indeed anyone security-conscious, will want to think twice about this drive, as it lacks AES 256-bit hardware-based encryption, which is found on many competing drives including the Editors’ Choice-winning Crucial P5.
At least the drive is durable, with a 750 terabytes written (TBW) rating for the 1TB version we tested and 500TBW for the 500GB model. TBW is an estimate of how much data can be written to the drive, according to the manufacturer, before some cells begin to fail and get taken out of service. The Gold P31’s scores are among the highest scores in its class; both the WD Blue SN550 and the Crucial P5 are rated at 600TBW for the 1TB version and 300TBW for 500GB, while the ADATA XPG Spectrix S40G rates at 320TBW for the 512GB model and 640GB for 1TB. Even the Editors’ Choice-winning Samsung SSD 980 Pro, a high-end PCI Express 4.0 SSD, falls short, with a 600TBW rating in its 1TB version, though the 1TB version of its predecessor, the Samsung SSD 970, is rated for a whopping 1,200TBW. All that said, the Gold P31’s five-year warranty is pretty standard for an internal SSD, although some companies cover their products for only three.
Then there’s the thorny issue of pricing. The 1TB version of the Gold P31 lists at $225, 22.5 cents per gigabyte, though you can get it through Amazon for a much lower $135, or 13.5 cents per gigabyte. List price for the 500GB version is $122, with it selling at retail for $75, or 15 cents per gig. Its retail pricing is neither absolute bargain-basement nor ritzy; among the better PCI Express 3.0 drives we have tested, the WD Blue SN550 retails for about 11 cents per gig for the 1TB version and 13 cents for the 500GB model, while the Editors’ Choice-winning Crucial P5 sells for 15 cents per gig for its 1TB model. The Samsung SSD 980 Pro retails at 23 cents per gigabyte.
Testing the Gold P31: Prepare for Launch Velocity
We run performance tests on PCI Express 3.0 SSDs—as well as internal SATA drives—on an Asus Prime X299 Deluxe motherboard with an Intel Core i9-10980XE processor clocked at a max boost frequency of 4.6GHz. We use 16GB of DDR4 Corsair Dominator RAM clocked to 3,600MHz, and the system uses an Nvidia GeForce RTX 2080 Ti Founders Edition as its discrete graphics card. (Read much more about PCMag’s testing procedures and what the results mean at How We Test SSDs.)
PCMark 10
Headlining the PCMark 10 test suite from UL—the world’s leading independent benchmark developer—is the overall PCMark 10 storage test, from UL, running the full storage suite, which simulates 23 different usage scenarios. This score represents how well a drive does throughout the entire PCMark 10 run. It’s the sanctioned score presented by UL’s software at the end of each run.
After that are some more granular measures, which represent simulations of how quickly a drive is capable of launching a particular program. These PCMark 10-derived tests represent a simulation of how quickly a drive is capable of launching a particular program or booting Windows 10 by recording how many megabytes per second the drive is reading what are known as shallow-queue 4K random blocks of data (the kind in which most applications, games, or operating systems are stored).
The Windows 10 Boot simulates the full Windows 10 operating system startup procedure and records how quickly the drive can feed the kind of data requested. After that is a game-launching test set, which simulates how quickly a drive can read shallow-depth small random 4K packages, one of the more commonly used file-block sizes for game installations. Although file block size depends on the title you’re playing, 4K small random read is the most accurate block-size metric relevant to these three popular FPS titles: Battlefield 5, Overwatch, and Call of Duty: Black Ops 4.
The drives are also put through an important test for creative types, simulating the launch of two very common graphics programs. As anyone who regularly works in programs like Adobe Premiere Pro or Photoshop can tell you, waiting for one of these programs to launch can seem interminable.
Last among the PCMark 10 benchmarks are the copy tests. Although these numbers may look low compared with the straight sequential-throughput numbers achieved in benchmarks like Crystal DiskMark 6.0 and AS-SSD, which are charted below the PCMark 10 scores, that is due to the way this score is calculated and the nature of—and differences between—the source data sets.
While the Gold P31’s score on the overall PCMark 10 storage test was merely average—the Crucial P5 led all the PCIe 3.0 drives we compared it with—it did much better on the launch and load tests in which it reads 4K data blocks. With the Windows 10 boot test, it was second only to the Samsung SSD 980 Pro— one of about half a dozen PCI Express 4.0 drives among the gaggle of SSDs we compared it with—with the Crucial P5 close on its heels. In the game-launch test, it bested all the other drives in both Battlefield 5 and Overwatch, and it essentially tied with the Samsung SSD 980 Pro in Call of Duty. In the Adobe creative program launch test, it was second only to the Samsung SSD 980 for both Premiere Pro and Photoshop, falling just short in Photoshop.
The Gold P31 led all the PCIe 3.0 drives we compared it with in the File Copy test, and all of them except the Crucial P5 in ISO Copy.
Crystal DiskMark 6.0 and AS-SSD
The Crystal DiskMark 6.0 sequential tests provide a more traditional measure, simulating best-case, straight-line transfers of large files, while the trio of AS-SSD tests involve copying large files or folders from one location on the test drive to another. The Gold P31 turned in pretty average scores in both the Crystal DiskMark’s sequential read test and the AS-SSD’s benchmarks, but performed in the top tier on the Crystal DiskMark 4K write test and was second only to the Samsung SSD 980 Pro in the 4K write test.
The Gold P31 was in the middle of the PCIe 3.0 pack in many of our benchmarks, but it really excelled at tests that involved reading 4K data blocks. This suggests a prowess in quickly handling tasks such as booting an operating system and launching applications or games. It bested even most PCI Express 4.0 SSDs in some of these tasks. Just about anyone can appreciate this, but gamers, photo and video editors, and other content creators will rejoice.
Verdict: Born to Zoom
Venerable semiconductor manufacturer SK Hynix only entered the branded consumer SSD market in 2019, but has leveraged its long experience in making memory chips into crafting quality internal SSDs, as we saw with the SATA-based Gold S31. The SK Hynix Gold P31 really knocks our SSD socks off by acing tests that emphasize speed in loading programs stored on it. Its relatively high terabytes written (TBW) rating suggests a long lifetime, and it is backed by a five-year warranty to boot.
Its software is limited to a clone/migration utility, and its lack of 256-bit AES hardware-based encryption may be a deal-breaker for business travelers and other security-conscious people; it’s best if you work from home or carry no sensitive data. The Crucial P5 is still our mainstream internal PCIe 3.0 NVMe drive of the moment to beat, but the aggressively priced P31 is impressive in its own right.
