PCIe 8’s incredible speeds break the terabyte bar

As predicted, your PC will internal pass a terabyte of data per second by 2028 as part of PCI Express 8.

According to the PCI Special Interest Group, the PCIe 8 specifications will be released in 2028 with speeds of up to 256 gigatransfers/second. In real-world terms that translates to 1 terabyte of data being transmitted per second over a PCI Express bus 8.0 x16 connection.

This new data rate is not surprising, as the SIG consistently releases iterative PCI Express specifications that double the bandwidth available about every three to four years. The PCIe SIG announced in June that the PCI Express 7 standard would be released by 2027. The SIG announced the existence of PCIe 8 at that time without providing bandwidth data. However, the projection was simple to make.

It’s a little confusing how everything happened. The fastest PCI Express devices, including the fastest PC SSDs currently available, use the PCI Express 5 Protocol — 128GB/s x16 speeds. The Micron 9650 was the first PCI Express 6.0 SSD to ship last week. It can theoretically process 256GB/s per time. They can’t in reality. The drive can read up to 28.000 MB/s, which is about 13 percent less than the maximum PCIe 6.0 bandwidth. Sequential writes are 14,000 MB/s.

This graphic shows the progression of PCI Express speed, but also gives a hint as to the hypothetical limits for certain components. SSDs use a x4 connection, so their maximum hypothetical data rate will be 256GB/s with PCI Express 8 versus 32GB/s for PCI Express 5. Graphics cards use a x16 interface, which means that PCIe 8 can provide about seven times the bandwidth of today.

The Micron 9650, however, is aimed at data centers, not the PC. Micron’s release of the 9650 coincides with our report that the PCI Express 6.0 integrator’s list of actual PCIe 6 hardware will be released this year, though data centers and AI may gobble up all of the available hardware. Silicon Motion’s CEO told Tom’s Hardware that the company PCI Express 6.0 is not expected to be available in PCs for several years .

The PCIe SIG says the same thing for the first PCIe 8.x devices: they will be used for artificial and machine learning, followed by high-speed networking, and then quantum computing.

As artificial intelligence and data-intensive applications continue scaling rapidly, PCIe’s high bandwidth, scalability, and power efficiency will ensure its demand in the long term. This is according to Reece Hayden of ABI Research. “Data center networks have already begun implementing PCIe 6.0 and are expressing great interest in PCIe 7.0 specifications. The introduction of PCIe 8.0 ensures that industry bandwidth requirements will continue to be met well into the future.

A terabyte’s worth of bandwidth, though, is no joke, and neither are the thermal issues that come with it. The two key problems that need to be addressed are when AMD, Intel, and Qualcomm plan to add PCI Express 6 to their PC roadmaps — let alone 7 or 8 — and how device makers will deal with the corresponding increase in heat that the increased bandwidth will bring with it.

Mark Hachman, Senior Editor, PCWorld.