The predisposition that “bigger is better” pervades in many areas, but in computing greater size is almost always a liability. Large configurations demand power and create heat. They consume precious space and potentially crowd out other vital systems. Even in a 60-ton armored tank, size, weight, and power (SWaP) remain at a premium. Such environments demand the sort of small form factor (SFF) solutions that have dominated embedded computing initiatives for decades.
Fortunately, computing manufacturers and standards groups have done remarkable work in bringing conventionally-sized systems down to diminutive proportions. Ever-shrinking circuit sizes enable one processor to contain the functionality of what previously required several discrete chips while delivering faster performance and consuming less total energy. Similarly, interconnects between components and devices continue to become denser and more efficient. Consider the now-ubiquitous Serial ATA hard drive interface compared to its Parallel ATA predecessor. The former is a fraction of the latter’s physical size yet offers roughly six times greater peak bandwidth (6 Gb/s vs. 133 MB/s, or 1.06 Gb/s). Similarly, the range of PCI Express connections available to system components enables ever-shrinking form factor possibilities while making leaps in performance bandwidth.