PCIe 5.0 SSDs Are Finally Here
THE PCI EXPRESS 5.0 specification was finalized on May 29, 2019. The first PCIe 5.0-ready consumer platform arrived with Intel’s Z690 chipset and socket LGA1700 platform in November 2021. (IBM’s Power10 processor was announced in 2020 and started shipping in mid-2021.) But PCIe 5.0 graphics cards and SSDs were nowhere to be found.
In fact, outside of certain Nvidia data center H100 solutions, PCIe 5.0 GPUs are still not here, but after waiting for over a year, the SSDs are starting to trickle out. The first crop of PCIe 5.0 M.2 SSDs all use Phison’s E26 controller. That’s an interesting point to begin with, as Phison at one point was regarded as one of the slower SSD controller options. That has changed a lot over the past several years, and the E26 now reigns as the fastest solution we’ve tested. It uses a dual ARM Cortex-R5 design with triple-core CoXProcessors—the coprocessors handle some common tasks, so the R5 isn’t a limiting factor, even though Cortex-R8 controllers are now shipping.
Coupled with the controller is a single LPDDR4 DRAM chip. All the 2TB Phison E26 products we’ve looked at so far are using a 32Gb IC, or 4GB of total RAM—twice the amount we’d expect to see. Whether that’s necessary to hit higher performance levels isn’t clear, but we’ve seen the same configuration on the Crucial T700, Corsair MP700, Inland TD510, and Gigabyte Aorus Gen5 10000. But the NAND is perhaps the bigger story.
The E26 is an eight-channel controller, and it can be paired with NAND operating at up to 2400 MT/s. Everyone so far is using Micron 3D NAND with 232 layers, but no one is using the maximum 2400 MT/s speed. In fact, most of the drives are using 1600 MT/s. That’s enough to go well beyond PCIe 4.0 speeds, but we’re not yet maxing out the PCIe 5.0 spec. Most of the drives are rated for 10,000 MB/s reads and 9,500 (give or take), though the Crucial T700 is the exception. It has 2000 MT/s NAND and is rated for 12,400 MB/s reads and 11,800 MB/s writes.
That might sound very fast, and it is. The real-world benefits, on the other hand, aren’t particularly noticeable. PCMark and 3DMark storage tests put the Gen5 drives at roughly 10–15 percent higher bandwidth than the fastest Gen4 SSDs. Copy testing was 15 percent faster as well, though the T700 was 20 percent faster than the top Gen4 drive. Only synthetic tests like Crystal Disk Mark and ATTO were able to show larger improvements. Latencies and useful random IOPS weren’t significantly changed.
Even if the performance is good, there’s still the power to contend with. These Gen5 SSDs all idle at around 3W of power. That’s not a problem for high-end desktops, but it’s not going to work with a laptop—not that any laptops currently offer PCIe 5.0 support. The higher interface speeds require more power, and PCIe 4.0 is still fast enough for all but the most demanding storage workloads.
But there’s another knockon effect: all these Gen5 drives require decent cooling. The Crucial T700 is available with a modestly sized heatsink that proved sufficient, but the Gigabyte Aorus has a massive heatpipe and radiator cooler. Inland’s TD510 has a tiny and noisy little fan attached to the heatsink. Is it necessary? Not in our testing, though in PCs with less airflow it might help. Corsair’s MP700 was supposed to include a fan and heatsink as well, but Corsair axed that, and instead requires that the motherboard have a sufficient cooler.
The good news is that prices on SSDs have plummeted over the past six months. The bad news is that while $280 for a 2TB PCI 5.0 drive might not sound too bad, that’s over twice what you’d pay for a Solidigm P44 Pro 2TB, one of the faster Gen4 SSDs. Even if your PC can support a Gen5 drive, you likely won’t notice the difference.
But never mind this. The PCI Express 6.0 specification was finalized in January 2022, and PCISIG is already working on PCIe 7.0. When will we get 6.0 platforms and drives? Check back in a couple of years.