Many companies tout the functional density of their single board computer (SBC) products, often stating that they have the highest functional density within a class of product. But what does this mean? How do you measure functional density? While performance can be measured with industry-accepted benchmarks, similar benchmarks for functional density do not exist.
This industry is now driven primarily by the bandwidth of the interconnects between the boards, not the microprocessor chips. That transition, from processor-driven to interconnect-driven, suggests that this industry now operates under a new set of laws.
Almost every backplane-based embedded computing system in existence has a board that is considered the controller. Over the years, the industry has often used the term Single Board Computer (SBC) to describe that board. The term is used because all of the basic computer functionality is integrated onto that one board: microprocessor, memory, and I/O. The functionality of SBCs has evolved in step with the advancements made in computer technology, with both the performance and functional density increasing many-fold since the first boards were introduced in the mid 1980s.