Intel unintentionally confirmed the existence of two of its upcoming client platform chipsets, the Z390 Express, and the X399 Express. The latest release-notes documentation of its Rapid Storage Technology driver, mentions Z390 and X399, alongside the CPU micro-architectures they support. The Z390 supports current-generation "Coffee Lake" and upcoming "Cannon Lake" processors, while the X399 supports HEDT derivatives based on the two architectures, namely "Coffee Lake-X" and "Cannon Lake-X," with no mention of "Skylake-X."

What happens to the X299, you ask? The table mentions the chipset as supporting SKL-X (Skylake-X) and KBL-X (Kaby Lake-X), but it's not clear if Intel is only referring to the forgettable i7-7740X and i5-7640X with "KBL-X." The Z390 is rumored as being Intel's next top mainstream-desktop chipset, with a long overdue update to onboard audio standards, in being a departure from the "Azalia" HD audio specification, onward to the new Programmable Quad-Core Audio with new SoundWire digital audio interface. The chipset is also rumored to feature 10 Gbps USB 3.1 ports.