The explanations behind this transfer may very well be a mix of last-minute cost-benefit analyses by Intel's bean-counters, and having to mass-produce Z390 Express on the busier-than-expected 14 nm silicon fabrication node, as against present 300-series chipsets being constructed on the 22 nm node that is nearing the top of its life-cycle. Intel in all probability wanted the change to 14 nm for the numerous will increase in transistor-counts arising from the extra USB controllers, the WiFi MAC, and the SmartSound logic. Intel in all probability does not have the vacant 14 nm node capability wanted to mass-produce the Z390 but, as its transition to future processes such as 10 nm and 7 nm are nonetheless saddled with setbacks and delays; and redesigning the Z390 (as we knew it) on 22 nm might have emerged unfeasible (i.e. the chip might have ended up too large and/or too scorching). The Z390 Express chipset block-diagram, which we revealed in our older article has been quietly faraway from Intel's web site. It is also rumored that this transfer might pressure AMD to rethink its plans to launch its Z490 socket AM4 chipset.
Source : TechPowerUp