Broadcom BCM5780 Mid-and-South Bridges (PCIe Power Mac G5)

When the Dual-Core PowerPC 970MP third-generation G5 CPUs came out in Mid-2005, Apple had to start using a brand new Mid Bridge chip for the Macs along with it. Since the AMD 8131 only had PCI-X bridges and no PCIe bus, they couldn’t keep the old chip, replacing it with the BCM5780. (Above: Block diagram […]

AMD-8131 PCI-X Midbridge Chip (2003-05 PCI-X Power Mac G5 only)

Have you ever wondered why there’s an AMD chip on the back of your Power Mac G5’s logic board, or what it’s even doing there? For higher end Mid-2003 thru Early 2005 Power Mac G5s, that’s the PCI-X “Mid Bridge” chip. This is what handles all your expansion cards! Although, it doesn’t appear in Late-2005 […]

IBM CPC945 Northbridge chip tech specs (Late 2005 Macs)

The IBM CPC945 is a redesigned Northbridge chip mostly for the Dual-Core PowerPC 970MP CPU. It has technical upgrades over the IBM CPC925, including a faster HyperTransport Bus. It’s also capable of talking to the PowerPC 970fx second-generation G5 chip, which means it may be found in other Late 2005 Macs on the logic board. […]