Note: Later AMD moved to LGA (AM5). AM4 remains the last mainstream PGA socket from AMD.
Pins for DRAM channels or PCIe lanes are not redundant. If a pin responsible for a specific memory channel is damaged, your PC may fail to boot or only recognize half of your RAM. am4 pin layout
: Control memory channels (A/B), PCIe lanes, and data transmission. A broken memory pin can disable an entire RAM slot. Note: Later AMD moved to LGA (AM5)
To prevent incorrect installation, the AM4 layout is with missing pins in specific corners. If a pin responsible for a specific memory
If you look at an AM4 CPU, you will notice several empty spaces (holes in the pin grid). These are reserved pins (RSVD) or "no connect" (NC) pins. AMD uses the same substrate for EPYC embedded and Ryzen desktop, so some positions simply do nothing on consumer chips.