| Feature | Specification | | --- | --- | | | 1331 pins (though technically, some are reserved or ground) | | Pin arrangement | 35 x 35 grid, but with large missing sections | | PGA type | µPGA (Micro Pin Grid Array) | | Pin pitch | 1.0 mm (distance between centers of adjacent pins) | | Pin diameter | ~0.45 mm | | Pin length | ~2.5 mm | | CPU substrate thickness | ~1.1 mm | | Triangle key marker | Bottom-left corner (when reading text on CPU upright) |
| Generation | CPUs | Pin-compatible? | Notes | | --- | --- | --- | --- | | 1000 (Summit Ridge) | Ryzen 7 1800X | Yes | Original layout | | 2000 (Pinnacle Ridge) | Ryzen 7 2700X | Yes | Minor power spec changes | | 3000 (Matisse) | Ryzen 9 3950X | Yes | PCIe 4.0 requires newer motherboards, but pins same | | 4000 (Renoir APU) | Ryzen 7 4700G | Yes | Uses additional GFX power pins | | 5000 (Vermeer) | Ryzen 9 5950X | Yes | Final AM4 CPU generation | | 5000G (Cezanne) | Ryzen 7 5700G | Yes | APU pinout fully backward-compatible | am4 pin layout
| Function | Approximate Location (Row, Column) | | --- | --- | | VDDCR_CPU (core power) | E15 to AE25 (large central block) | | VDD_SOC | H8 to N12 (near bottom-center) | | VSS (ground) | Interspersed, but heavy at edges | | DDR4 Channel A DQ0 | B12 (bottom left edge of active area) | | DDR4 Channel B DQ0 | B24 | | PCIe x16 Lane 0 RX | U3, U4 | | PCIe x16 Lane 0 TX | AA3, AA4 | | Reset_L | V28 | | PROCHOT | W30 | | SVI2 data | AJ10 | | 100MHz REFCLK | K31, K32 | | Feature | Specification | | --- |
| Feature | AM4 | AM5 | | --- | --- | --- | | Type | PGA | LGA | | Pins on | CPU | Motherboard | | Total contacts | 1331 (nominal) | 1718 | | Memory | DDR4 | DDR5 | | PCIe | Gen 3/4 (CPU dependent) | Gen 5 native | | Triangle key | Yes | Yes (but smaller LGA key) | Compatibility issues were BIOS/chipset-based, not pin-based
Any AM4 CPU fits physically into any AM4 socket. The pin layout never changed. Compatibility issues were BIOS/chipset-based, not pin-based. 7. Common AM4 Pin-Related Problems and Solutions 7.1 Bent Pins on the CPU Symptoms: No boot, debug LEDs on motherboard (CPU LED lit), memory detected incorrectly, PCIe devices missing.