So if I were to speak of the best in PCIe 5.0 SSDs going mainstream, it would have to be the efforts and success in finding a higher performing yet cooler storage solution.  This wasn’t so much the case with Gen4 and I think we seemed to get used to the fact that Gen4 SSDs, for the longest time, ran very hot.  Gen 5 experienced this start as well. Our report today is going to examine Phison’s latest E28 8-channel Gen5 reference design SSD controller which moves things a step forward from the Phison’s last E26 Gen5.  Although the E26 was the industries highest performing SSD for some time and enjoyed a great deal of success, its speed did come with a price and that was the rather high active power ratings which translated to heat and the need for a cooling solution.

When I speak of cooler, at least in my terms, I consider the fact that newer Gen5 SSDs are having much more success in their use in laptops and ultras, and even without the direct need for a heatsink.  We have seen this with the success of the Silicon Motion SM2508 8-channel Gen5 SSD controller which has now garnished amazing success in the SSD industry and, at least as of the writing of this report, is probably the SSD controller to beat for top spot.

One thing is certain which is that our library of Phison evaluation samples has grown over the past few years.  Those early samples were sporting eight NAND chips and two DRAM chips along with the SSD controller. Let’s take a look and see what sets the newest Phison PS5028-E28 Gen5 8-channel SSD apart from the rest.

The Phison PS5028-E28 Reference Design is a PCIe 5.0 x4 (4-lane) 8-channel SSD  controller that relies on the latest NVMe 2.0 SSD operating protocol.  Our sample SSD is comprised of the E28 controller set into a black 2280 (22mm wide x 80mm long) M.2 PCB (printed circuit board) which also contains a DRAM cache chip and two pieces of KIOXIA BiCS8 218-layer 3D TLC NAND flash memory.

The E28 is of a 6nm Gen5 SSD controller that speaks to low 6 watt sequential power draw which bumps just a bit below 7.5 watts for random sustained read and drops to about 5.5w for random sustained write.  Phison believes that the E28 has the lowest idle power consumption of all comparable products available today at 1.31w.

This SSD is a single-sided SSD and, by composition, should be one of the highest performing and coolest Gen5 SSD solutions available on release.  Its performance is listed as 14900MB/s read and 14000MB/s write and should be available in 1,2 and 4TB capacities.

The theoretical high for 2/4TB versions of this SSD are above 2.5 million IOPS read and 3 million IOPS write.  We haven’t been able to reach these highs just yet, however, thought it an interesting point to note.

As a point of clarity, our sample Phison E28 Gen5 SSD is a reference design early sample which has been provided to select members of the review community, along with Phison Partners as an early preview of what is coming.  It’s official release to partners is an estimated 30-45 days away, the final product which should contain a higher performing final optimized production firmware.  This report is a ‘preview’, if you will, of what will be available from SSD companies in the near future.

Let’s take a look at the performance.