With the Exceria Pro, Kioxia is finally offering a high-end M.2 NVMe SSD with PCI-Express 4.0 support. The company was wise to pick the Phison E18 controller to power their latest release. We've encountered the Phison E18 in many recent reviews—it has catapulted Phison from being an interesting midrange SSD controller vendor to the market leader within a short time. In terms of PCB design, Kioxia made only minimal changes and is using the Phison reference PCB design—just like most other companies. This is certainly a valid approach as Phison probably knows best how to design an SSD that works well with their own controller. As expected, a DRAM cache is included for the mapping tables of the SSD, which helps with random writes. Kioxia doesn't confirm or deny the use of the Phison E18, we're 100% certain though that that's the controller in use.

The TLC NAND flash chips are Kioxia's newest 112-layer BiCS5, which is a big difference to all the other Phison E18-based drives I've reviewed so far, as those are all using Micron 96-layer or 176-layer NAND. It's interesting to see how there's certain benchmarks where the Kioxia flash has the upper hand and others where the Micron NAND is faster. Overall synthetic performance results are very good, near the top of our scoreboards, which is expected of any drive using the E18 controller. Phison made sure a lot of optimization went into getting these synthetic scores high enough, which is why our real-life testing is so important—it runs actual applications, something that's much harder to optimize for. Our real-life testing is also performed with 80% of the drive filled, which is a more realistic scenario and limits the drive in the way it uses its pseudo-SLC cache.

In our real-life test suite, the Kioxia Exceria Pro achieves impressive results that are higher than all PCI-Express 3.0 SSDs we ever tested. The performance uplift to the Kioxia Exceria is 8%, and 4% to the Kioxia Exceria Plus G2. Only a few drives are faster than the Exceria Pro, all by a tiny 2%. These are the Kingston KC3000, Samsung 980 Pro, WD Black SN770, and WD Black SN850. This makes the Kioxia Exceria Pro an excellent choice if you're looking for a high-performance PCI-Express 4.0 SSD. Value M.2 NVMe drives are up to 15% slower, and the aging SATA drives are at least 25% behind.

The pseudo-SLC cache of the Kioxia Exceria Pro is reasonably sized with 200 GB, but some competitors offer even bigger caches. Unless you have huge write loads, you'll never get to the point where this makes any difference. Filling the whole drive with data completes at 1.2 GB/s, which is a good result, but lower than the PCI-Express 4.0 top dogs that reach around 2 GB/s. Again, this might be completely irrelevant to you unless you have a source that can provide data at such an enormous rate. 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.

Kioxia doesn't include a heatsink with their drive; the sticker is just plastic. Other companies offer something with a bit of copper in there that helps spread the heat around. It also seems heat output from the Kioxia flash is a bit bigger than that of Micron because we're seeing considerable thermal throttling in our stress-test scenario. Unlike other drives, where performance basically stops, the Exceria Pro's throttling is well-behaved and performance drops more gradually. Considering the positioning and pricing, it would be nice if Kioxia could include a heatsink with this SSD.

According to Kioxia, the 2 TB version of the Exceria Pro will sell for €299 including 19% VAT. Unfortunately, Kioxia's drives aren't sold in the United States, so we converted that price to $280 without tax. At that price point, the SSD is priced similarly to other high-end PCI-Express 4.0 drives, maybe a little bit on the high side. Strong competition comes from the WD Black SN850, which costs $260, and the Samsung 980 Pro for $250. Both are a tiny bit faster than the Exceria Pro and more affordable. Kingston wants $340 for their KC3000, I'd pick a $280 Exceria Pro over it any day. The Corsair MP600 Pro is $299, but comes with a heatsink. I still feel Kioxia will have to adjust their pricing a bit, much closer to $250, to appeal to the masses. An interesting alternative is the WD Black SN770, which is DRAM-less, still offering impressive performance, and priced very affordably at $230. If you can live with slightly lower performance, PCI-Express 3.0 SSDs are also worth considering as the real-life differences aren't that big. As always, do check the prices of your local market as there often are huge differences between geographic regions—it's all about the pricing.