Common System Interface (CSI) A point-to-point processor interconnect being developed by Intel to replace their processor front side bus interface. CSI is defined as a variable width, point to point, packet-based interface implemented as two uni-directional links with low-voltage differential signaling. A full width CSI link is physically configured with 20 bit lanes in each direction; these bit lanes are divided into four quadrants of 5 bit lanes, providing 12-16GB/s of bandwidth in each direction.
The Common System Interface is called the QuickPath Interconnect.
Currently the Common System Interface is used on both the Xeon and Itanium based processors produced by Intel. Xeon processors are the normal desk top series of PC processors, while the Itanium processors are geared toward the server market.
This site considers the CSI bus as an IC-to-IC interface, under the Buses icon below.
IC Bus Descriptions, IC Manufacturers, and Processor Manufacturers
