If you Google the word “SWaP” you get some interesting search results. Most are finance related and here’s a definition of swap from Wikipedia: “In finance, a swap is a derivative in which counterparties exchange certain benefits of one party’s financial instrument for those of the other party’s financial instrument. The benefits in question depend on the type of financial instruments involved.”
Now that’s a defination that only a lawyer could love!
Our use of the term “SWaP”, as you might expect, comes from the military system specifications that require certain size (S), weight (W) and (a) Power (P) savings in military systems. To some extent SWaP design requirements are concerned with portable systems – the obvious reasons are that military equipment carried into the field of battle must be as small and lightweight as possible with long operating intervals between required battery recharges. However, rackmount computer equipment mounted in ground vehicles, ships, submarines and military aircraft can deliver similar application benefits when systems are designed with an eye toward SWaP savings.
Trenton recently introduced the world’s first dual processor, MicroATX embedded motherboard that features quad-core processors and PCI Express 2.0 option card support. This Mil-COTS product is called the JXM7031 embedded motherboard and it provides siginificant SWaP savings over traditional motherboards. Here is a break down of the SWaP savings possible using a MicroATX motherboard vs. an ExtendedATX motherboard:
| JXM7031 MicroATX (uATX) Motherboard | Traditional EATX Motherboard | SWaP Percentage Savings with uATX | |
| Size (S) | 92.16 in2 | 156 in2 | 69.3% |
| Weight (W) | 5.6 lbs | 4.14 lbs | 35.3% |
| Power (P) — +5V rail | 0.92A | 4.61A | 401% |
| Power (P) — +12V rail | 12.20A | 13.70A | 12.3% |
| Power (P) — +3.3V rail | 1.98A | 2.56A | 29.2% |
Trenton JXM7031 MicroATX Motherboard
The savings illustrated here are based on system testing that we have done in our engineering labs. The actual SWaP savings you obtain will be higher or lower depending on the design parameters of your system application. Our comparisons are based on the two motherboards only, so your size and weight savings will likely be higher due to the smaller chassis that can be used with the JXM7031 uATX motherboard. Your power savings will also vary based on the number and type of option cards used in the system as well as the amount of system memory installed in the motherboard.
Hopefully this information is helpful in applying SWaP analysis techniques for your rackmount computer designs. See our embedded motherboards page and industry solutions web page for more product and application information, or contact a Trenton account manager at 800.875.6031 or 770.287.3100 to design a customer-driven computing solution that meets your exact requirements.
