The Kioxia Exceria SATA SSD has been on the market for a while. It's based on the OCZ/Toshiba TR200 released before the company changed its name to Kioxia. Under the hood, we found a Phison S11 controller, rebranded as Toshiba, and 64-layer 3D TLC NAND from Toshiba, too. Kioxia wasn't willing to confirm these findings, but they confirmed that "any change to controller/DRAM/flash will introduce a new model number", like "Exceria G2". Both of these controller and flash are based on aging designs, which makes it difficult for them to compete with more modern solutions. While it makes perfect sense from a price perspective, the lack of DRAM cache further limits performance. On an SSD, the DRAM cache is used to buffer the mapping tables of the SSD, which keep track of where a certain piece of data is located. Basically, it translates between linear disk addresses as seen by the operating system and the actual location of the data—which NAND flash chip at which address in that chip.

While the latest controllers have several mitigations to still achieve good random write performance even without DRAM, the Phison S11 lacks all that and seriously falls behind. This is clearly visible in our DRAM-less testing on page 5, where the numbers are really a fraction of what competitors offer even for small test area sizes, which are representative of consumer workloads. In other synthetic tests, the Exceria SATA did better, especially random read was good, reaching the best result of all the SATA drives we ever tested. Sequential throughput was also fine, reaching well over 500 MB/s read and over 400 MB/s write, which is similar to the competition.

Once we move away from synthetic tests and to real-life workloads, with the drive to 80% full, things look a bit different. While many test results are "good enough," and considerably better than what any mechanical HDD offers, the Kioxia Exceria SATA is surprisingly weak in other tests, like WinRAR compression and MP3 import—both comprised of random writes and random reads. These are probably challenging due to the lack of DRAM cache. Overall performance is clearly better than QLC SATA drives, like the Crucial BX500 and Samsung 870 QVO. High-end SATA drives, like the Crucial MX500, Seagate Barracuda, and Samsung 860 EVO, are a good deal faster, though. Typical M.2 NVMe drives are around 40% faster, with the best Gen 4 drives offering a 60% performance uplift, albeit at much higher pricing, of course. Still, if you're planning on upgrading an older HDD-based system, the performance improvements will be amazing.

Write intensive performance of the Kioxia Exceria SATA is better than the various QLC SATA drives, but with 200 MB/s on average to fill the whole capacity, it's still far from the 400+ MB/s you're ideally wanting from a high-end SATA drive. The pseudo-SLC cache is also rather small with 20 GB, but that's plenty if you're hitting the drive with light consumer workloads only. Also, these loads have their activity spaced some time apart, which gives the SLC cache additional time to regenerate.

Priced at roughly $80, the Kioxia Exceria SATA is a highly affordable SATA SSD. For this product, the price is what makes or breaks it. At $80 or below, it's tempting if every dollar counts, but higher-end SATA drives like the MX500 are only marginally more expensive at $85-$90. Once you up your budget to $100, which might not be much in absolute dollars, but is still a 20% increase, you should probably consider an M.2 NVMe SSD as that offers considerably higher performance and is more convenient in terms of form factor; that is, if you have a free M.2 slot. If you absolutely need a SATA drive, the Kioxia Exceria SATA could be an option, especially if you have light workloads that are mostly read-heavy.