iPhone Air is the big newcomer among Apple's latest lineup that went on sale Friday, but inside the slim phone's raised plateau is another new piece of hardware that signals a renewed focus on artificial intelligence. Apple's custom A19 Pro chip introduces a major architecture change, with neural accelerators added to each GPU core to increase compute power. CNBC's Katie Tarasov explains. Full report: cnb.cx/3IqBo2O | CNBC