Am4 Pinout -

| Lane Group | Destination | |------------|-------------| | | Primary PEG (PCIe x16 slot) | | Lanes 16–19 | M.2 NVMe (direct to CPU – “M2_1”) | | Lanes 20–23 | Chipset (downlink – PCIe 3.0 or 4.0) |

Here is the technical content regarding the (the socket used for AMD Ryzen CPUs, including 1000 to 5000 series, and some 4000-series APUs). Note: The AM5 socket (Ryzen 7000+) uses an LGA design and has a completely different pinout. The following applies only to AM4 (PGA – Pin Grid Array). 1. Basic Specifications | Feature | Detail | |---------|--------| | Type | PGA (Pin Grid Array) – pins are on the CPU | | Pins | 1331 pins (often referred to as Socket AM4, 1331) | | Pin Arrangement | 32×32 grid with missing pins in central area | | Pitch | 1.0 mm | | Keying | One corner has a missing pin (triangle marker) | Key fact: Despite having 1331 pins, many are VSS (Ground) or VDD (Power) for signal integrity. 2. Pin Groups (Functional Categories) The pins are divided into these major groups: am4 pinout

Corner with triangle marker (missing pin) is key. Row A: A1 (VDD18) A2 (VDD) A3 (VDD) A4 (VSS) ... Row B: B1 (VDD18) B2 (VDD) B3 (VSS) B4 (VSS) ... Row C: C1 (PWR_OK) C2 (VDD) C3 (VDD) C4 (VSS) ... ... | Feature | AM4 (PGA) | AM5 (LGA) | |---------|-----------|-----------| | Pins on | CPU | Motherboard | | Pin count | 1331 | 1718 | | DDR type | DDR4 | DDR5 | | PCIe | 3.0/4.0 (CPU dependent) | 5.0 | | Lane Group | Destination | |------------|-------------| |