I have to say I'm impressed with the performance gains achieved by switching from 96-layer Micron TLC NAND to the company's newest 176-layer technology. No doubt, Phison has added firmware tweaks to their new platform, but the most significant gains are from the new flash design, which offers performance improvements, especially when running with low queue-depth, which is very important for consumer-oriented applications.

Averaged over our real-life test suite, Phison's sample achieves better performance than Samsung's 980 Pro, and, as expected, beats the Corsair MP600 Pro, too, which uses the same E18 controller, but older 96-layer flash. Only the WD Black SN850 is able to match the Phison drive—both are the fastest SSDs we've ever tested. Compared to the fastest PCI-Express Gen 3 SSDs, the performance difference is 5 to 10%, with bigger differences depending on the workload. More value-oriented M.2 NVMe drives are up to 15% slower and old-school SATA SSDs are up to 50% slower.

Synthetic numbers of Phison's new SSD are even higher—it clearly is the fastest drive in our test group. No doubt a lot of optimization went into getting these high enough to beat the competitors. That's 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.

While the performance gains are certainly impressive, the much bigger revelation, at least in my opinion, is how much sustained writes have improved. Up to today, even the fastest TLC SSDs would only achieve 1.5 GB/s with their pSLC cache exhausted. The new 176-layer NAND more than doubles that. We were able to fill the whole 2 TB capacity of the drive at 3.15 GB/s, which is faster than even the MLC-based Samsung 970 Pro. Yup, you read right—the 970 Pro is finally beat.

Phison shipped our sample drive with a great heatsink preinstalled, which avoids thermal throttling completely. Of course, the choice of heatsink, if any, is up to the SSD vendor, so this might not be representative of what to expect on the market. That's why I also tested the drive without the heatsink and any airflow. Here, we do see some thermal throttling, which isn't surprising. The throttling is extremely well-behaved, though—write speeds still remain high, reaching over 3 GB/s. For the first 100 seconds, there's no throttling at all; in those 100 seconds, we wrote over 500 GB/s of data, something that's very unlikely, especially for consumer workloads.

Phison didn't indicate any pricing, and even if they did, with Chia crypto-mining, prices are quite unpredictable at the moment. Still, I don't expect these drives to be much more expensive than other top-end competitors. For example, the WD Black SN850 2 TB costs $420, but lacks a heatsink. The version with a heatsink costs $550 (expensive!). Samsung's 980 Pro 2 TB is currently $600 without a heatsink, but with Samsung tax. The Corsair MP600 Pro is $457 including a heatsink. I feel like I'd be willing to spend $30 or so on top of that for the gains of the new NAND flash, but certainly not more than an extra $50. I'm really looking forward to seeing the Phison E18 + Micron 176-layer NAND combo in action on retail drives—heated up competition will be good for us customers.