Direct Connect Architecture

The Direct Connect Architecture is the I/O architecture of the Athlon64 and Opteron microprocessors from AMD. It consists of the combination of three elements:

• The microprocessor is directly connected to DRAM memory through an integrated memory controller.
• The microprocessor is directly connected through a natively implemented Hypertransport to a high performance I/O subsystem.
• The microprocessor is directly connected to other CPUs through a proprietary extension running on top of two additional natively implemented Hypertransport interfaces allowing support of a cache-coherent Non-Uniform Memory Access multi-CPU memory access protocol and Symmetric multiprocessing.