| Feature | AM3+ | AM4 | |--------------------|---------------|---------------------------| | CPU pin count | 942 | 1331 | | DDR support | DDR3 | DDR4 (only) | | PCIe CPU lanes | 16 (2.0) | 20 (3.0/4.0) | | Unified power rail | VDD only | VDD + VSOC (separate) | | SVI interface | SVI 1.0 | SVI2 (higher granularity) | | No chipset needed? | No | Yes (but FCH integrated) |
Perhaps the most significant divergence visible in the AM4 pinout, when compared to its predecessors, is the native integration of the memory controller. The diagram includes dedicated pins for dual-channel DDR4 memory support. Previous AMD sockets often relied on a northbridge on the motherboard to handle memory, but the AM4 pinout brought these signals directly to the CPU package. This reduced latency significantly and allowed for higher memory frequencies. am4 pinout diagram