We finally have a confirmation of Z390 chipset supporting existing Coffee Lake S CPUs.
SuperMicro Z390
This is the first trace of SuperMicro’s upcoming Z390 motherboard (C9Z390-CG-IW). What is particularly interesting about this leak is the fact that this motherboard was equipped with Core i7-8700T processor, the low-power 6-core CPU already available in stores. Update: we also have a proof of Z390 supporting Core i7-8700K (added below).
This means that Z390 will support both upcoming 8-core and existing 6-core 8th Gen Core CPUs. In other words, the Z390 has the same LGA1151 socket as other 300-series motherboards.
Either way, if we were to speculate about the Z390 platform launch period, we are probably one or two months away, judging from the timing of this leak.
Z390 + Core i7-8700T:
Z390 + Core i7-8700K: