The Infiniband interconnect technology makes use of a channel-based, switched-fabric, point-to-point architecture to deliver new levels of scalability, availability and performance. Scalability may be the most important benefit of the technology and is delivered in part by its switched network interconnect, automatic reconfiguration of the network upon addition or removal of devices and the use of virtual channels rather than hardwired links to connect servers to other devices. This scalability results in incremental performance increases when servers, peripherals or switching elements are incrementally added to an Infiniband system. This is in sharp contrast to today's systems where small and diminishing returns may be realized from plugging yet another PCI device into an already saturated shared bus.
With "six nines" as the buzzword goal of almost the entire computer industry, availability is the second crucial component of the Infiniband value proposition. Availability is a product of reliability, fault tolerance and serviceability. Infiniband technology utilizes point-to-point interconnects, allows for redundant paths between devices with subsequent failover capability and includes improved error detection and correction, all of which increase the reliability of the system.
The ability to hot-swap devices and have the network automatically reconfigure itself results in direct serviceability improvements.
Finally, performance is the necessary but insufficient component of the Infiniband benefit set. Performance is a check-off item that needs to be high enough to keep the computer industry from taking a step backward, but an item that, in isolation, would probably not convince the industry to move to a new technology almost regardless of the magnitude of the performance improvement. The most salient aspect of performance is the data-transfer rate of Infiniband's architecture.
Data is transferred between Infiniband fabric elements on links of copper cable or optical fiber. In the case of copper cable, links comprise pairs of unidirectional differential interconnects, with one differential pair for each direction. This topology is described as "dual simplex" and results in full duplex data transmission.
Beyond the raw data transfer rates, system-level performance is improved by the Infiniband architecture's concept of intelligent channels, whereby computing intelligence is distributed into the I/O system itself to off-load processors from the task of controlling I/O.