Several pins are dedicated to USB 3.0/3.1/3.2 Gen 1 and Gen 2 signals coming directly from the CPU, reducing latency compared to chipset-controlled USB ports.
If you look at the CPU upside down (pins facing you), the layout is divided into four rough quadrants based on function:
Pin density note: Power pins are usually multiple per rail to handle high current (up to 150A for high-end Ryzen 9). am4 pin layout
The pins are organized into several functional zones around the central die area:
Example approximate layout (logical, not to scale): Several pins are dedicated to USB 3
Legend: P=Power, G=Ground, S=Signal, K=Key
Top-left (pin A1 start)
A01 A02 A03 ... -> G, P, S, S, G...
B01 B02 ...
...
AM4 uses PGA (Pin Grid Array). Unlike Intel’s LGA (Land Grid Array), where the pins are springy contacts inside the motherboard socket, AMD puts the pins directly on the CPU. The motherboard socket (usually an AM4 socket like the b450, x570, or b550) features spring-loaded holes that the CPU pins drop into.
Do not probe pins with a multimeter while the system is powered unless you have a precise reference. Incorrect voltage probing can short power planes and destroy the CPU or chipset. If you look at the CPU upside down
If you need a literal pin-to-pin coordinate map (e.g., "what is at position D15?"), please specify the exact pin coordinate, and I can provide its known function based on community-sourced data.