Asus and ASRock releasing new BIOS updates (including Spectre fix) which including a new U0-stepping for Coffee Lake CPU’s. Until now Kaby Lake and Coffee Lake CPU’s were identical, they both had the B0 stepping – this is going to change now. In fact until the stepping change the Coffee Lake CPU’s are only re-labeled Kaby Lake CPU’s because everything else is identical.
The change from B0 to U0
According to this paper here this new stepping change means that we see DDR4-2666 support for the Coffee Lake processors. There is no other change except this. Every mid-range CPU (Dual-/Quad-Core) with the ID 085 & 090 are affected by this change.