"AMD sockets AM4 is a Pin Grid Array socket with zero insertion force. It maintains the same locking mechanism as the previous generation and takes up exactly the same area as AM3+, measuring in at 40x40mm. One of the most significant changes however is the number of pins. AM4 supports 1331 pins which is a very significant increase over the 942 of AM3+ and quite a bit more than Intels LGA1151. All AM4 APUs & CPUs featured integrated southbridges and natively support significantly more PCIe lanes & USB devices than before.That in addition to AM4s cross-compatibility feature have been the primary drivers of the hefty 40%+ growth in pin contacts from AM3+ to AM4. To accommodate this the number of traces going in and out of the socket has also increased dramatically. This has unfortunately necessitated and adjustment of the sockets cooler/heatsink mounting holes. Effectively breaking compatibility with all previous generation coolers for AM2, AM2+, AM3 & AM3+." [WCCFTECH] via [Frostytech.com]
