While AMD's Ryzen processors generally chat directly with graphics cards and NVMe storage devices over 8 GT/s PCIe 3.0 lanes, peripherals attached through existing 300-series chipsets are limited to the bandwidth offered by PCIe 2.0 lanes. The company's upcoming 400-series chipsets could bring PCIe 3.0 capabilities to all slots of future Ryzen motherboards, according to recent updates in the PCI-SIG Integrator's List.
As a refresher, AMD's Ryzen chips communicate directly with storage devices over four dedicated PCIe 3.0 lanes, with another 16 top-speed lanes set out for one or two graphics cards. Another four PCIe 3.0 lanes attach the chipset to the CPU. All chatter between the chipset and any other PCIe devices is then of the 5 GT/s PCIe 2.0 variety. AMD's current top-of-the-line mainstream desktop chipset, the X370, has up to eight PCIe 2.0 lanes.
For just one possibility, this rumored change likely opens the door for future motherboards with two PCIe 3.0 x4 M.2 slots: one wired directly to the CPU and the other connected to the chipset. It's not clear whether the maximum number of PCIe lanes will increase along with the speed upgrade, however, a change that would make 400-series chipsets potentially more competitive with the maximum of 24 flexible PCIe 3.0 lanes available from Intel's Z370 chipset.
The "upcoming changes" section of HWinfo's HWinfo32 and HWinfo64 5.70 release notes add further smoke to the fire around AMD's 400-series chipsets. AMD has offered no information at all on the subject so far, however. We'd guess the 400-series chipsets will likely be released around the same time as the company's second-generation Ryzen CPUs sometime next year, if such a release is in the works to begin with.