In taking apart the new iMac Pro, iFixit discovered an Apple chip identified as "338S00268," which the repair experts said "appears to be the rumored A10 Fusion coprocessor." Notably, the chip discovered near the solid-state hard drive is separate from the T2 chip, which handles secure booting, password encryption and more.
The discovery of a second Apple chip could refuel speculation as to what exactly the hardware is for.
Prior to the shipment of the iMac Pro, developers found indications in macOS High Sierra that an A10 processor could be included inside of the machine, generating rumors that the iMac Pro might boast always-on "Hey Siri" support and more. However, no such capabilities were found once the machine shipped, suggesting the custom silicon serves a different purpose.