Phison PCIe gen 4 SSD is faster than Optane SSD

Businessman in superman pose

Phison is showcasing an unreleased PCIe 4.0 controller CES 2021 that is faster than Intel’s P5800X Optane SSD.

Update: PCIe Gen 4 bus saturation point added. 12 Jan 2021.

The Taiwanese NAND flash vendor said it plans to launch PCIe gen 4 controllers this year. PCIe gen 4 is twice as fast as PCIe gen 3, at 2GB/sec per lane versus gen 3’s 1GB/sec.

The PS5021-E21T (E21T), built with 12nm technology, delivers up to 25 per cent improvement in performance and power consumption over the previous 28nm generation. According to Phison, this means the PCIe 4.0 E21T is good for console, PCs laptop, and mobile gaming – and here are new design-in opportunities.

The PS5018-E18 is Phison’s second, faster, PCIe Gen 4×4 NVMe SSD, delivering up to 7.4/7.0 GB/sec for sequential read and writes. This is faster than the 7.2GB/sec sequential read speed of Intel’s P5800X Optane SSD, which also uses PCIe Gen 4.

An industry source suggests that both the Optane and Phison drives are saturating the PCIe gen 4 bus. Also, some of the difference between the Phison and Optane drive numbers could be due to how speeds are reported, SI-based numbers versus non-SI numbers for example.

Phison beats the  6.9GB/sec of Kioxia’s CM6 2.5-inch SSD, 6.3GB/sec of KIoxia’s XG7 M.2 format drive, and 6.2GB/sec of Kioxia’s CD6 M.2 drive.

We don’t know what kind of flash the Phison controller is driving, although we think it is Micron TLC flash. All the Kioxia drives above use 96L3D NAND formatted as TLC flash.

The E18 controller supports up to 8TB capacity and, we think, 1 million random read IOPS. Phioson also said the E18 has superior power efficiency, but did not say what it is superior than.

N.B. PCIe 4.0 may be twice as fast as PCIe 3.0, but this does not also mean that SSDs using the technology are also necessarily twice as fast. For example, a PCIe 4 SSD that uses QLC flash will probably out-run an PCIe gen 3 SSD that uses faster TLC NAND memory. But there will not be a doubling of performance.