It’s been a long time coming but the PCIe 4.0 standard is almost upon us. PCI Express 4.0 will officially be supported by AMD’s upcoming Ryzen third-gen Matisse CPUs but in the meantime, Phison, a Taiwanese manufacturer of NAND flash controllers, has been showing off its E16 NVMe SSD controller during demo sessions at CES 2019.

The new PCIe 4.0 standard represents the first jump forward in the motherboard expansion slot for the best part of nine years. PCIe 4.0 has many benefits but the chief advantage is it doubles the bandwidth of the PCIe lanes and therefore improves data transfer rates. The PCIe 4.0 specification delivers 16GT/s data rates in comparison to 8GT/s on PCIe 3.0.

Enough of the theoreticals though because the reality is that PCIe 4.0 is capable of beastly performance. Phison’s SSD benchmark used CrystalBenchmarkTest to test the read and write performance of an SSD interfacing through PCIe 4.0. In the benchmark, Phison achieves 4GB/s of sequel read and a pretty mind-blowing 4.2 GB/s of sequential write performance.

While it’s slightly tangential, Xquatrox’s piece on SSD slowdown issues does delve into what sort of read and write speeds you can expect from an SSD using PCIe 3 and there is a stark change with the jump to PCI 4.0. In those particular benchmarks, we see it max out at 3GB/s read and 1.8GB/s write speed, compared to 4 GB/s read and 4.2 GB/s write speed with PCIe 4.0.

Phison anticipates that once officially supported SSDs come to market with the E16 NVMe SSD controller we can expect to see even faster speeds of 4.8 GB/s read and 4.4 GB/s write performance.

For the end user, the benefits of this speed increase are two-fold. Firstly, we’re going to be able to move big files around faster than we ever have before. 4.4 GB/s sequential write speed is lighting fast, particularly when stacked up against the 80-150 MB/s write speed of modern 7200 RPM hard drives. In addition to this, we have the improved responsiveness. The E16 controller is capable of 900,000 IOPS and should deliver very speedy operating systems and software.

There are no motherboards that actually support PCIe 4.0 just yet but we're expecting to see the first of them begin to roll out in the next few months, in all likelihood alongside AMD's Matisse processors.