Most of the details of the design and fabrication of microprocessors are not public. A major source of information on these components is actually various analyses performed by enthusiasts using the detailed die shots released by Intel, NVIDIA, and AMD. One component we’d been lacking a die shot for was the cIOD, or “I/O die” on Zen 4 processors,

Source: Hot Hardware – AMD’s Zen 4 I/O Die Shot Reveals A Fascinating Ryzen CCD Detail