A discipline from defense & aerospace engineering
SWaP-2C
Size · Weight · Power · Cost · Cooling
The five constraints engineers optimize together to field capability at the edge. Never one at the expense of the rest. Every gram, watt, dollar, and degree is a budget. JoulesPerBit brings that same budget to software and AI, where it has been missing.
The five constraints
One budget, five line items
Size
The physical footprint a system occupies. On a platform, every cubic inch is contested space.
Smaller fits more places, but density forces every other constraint to fight harder.
Weight
The mass a platform must carry. Mass costs fuel, range, and payload on everything that moves.
In airborne ISR, removing one pound can save on the order of $30,000 over a platform’s life.
Power
Energy drawn to do the work, and the heat that draw creates. Watts are batteries, runtime, and range.
The constraint the AI era runs into first. Every watt spent must return useful work.
Cost
Procurement and lifecycle expense. Added to SWaP because miniaturization drove price and obsolescence up.
Capability that cannot be afforded, at scale and over time, cannot be fielded.
Cooling
Thermal management. Added last because as parts shrank, heat density climbed until cooling set the ceiling.
Past a point you are not limited by compute. You are limited by how fast you can move heat.
How the budget grew
SWaP → SWaP-C → SWaP-2C
The original
Size, Weight, Power. The first budget for anything fielded at the edge: do the most, in the least, on the lightest.
+ Cost
Extreme miniaturization drove procurement and lifecycle expense up. Cost joined the budget so capability stayed affordable.
+ Cooling
As parts shrank, heat density climbed until thermal management became the limit. Cooling completed the budget.
The whole budget
You cannot win one axis for free
Push on one constraint and you pay on the others. Shrink the size and heat density rises. Cut power and you trade away performance. SWaP-2C is the discipline of the whole budget, not any single number.
A leaner footprint means pulling inward on every axis at once. That is the shape we engineer for: less size, weight, power, cost, and cooling, for the same useful work.
SWaP-2C, applied to bits
Hardware lived by this budget.
Software never got the memo.
For decades, anything that flew, sailed, or deployed to the edge was built to a SWaP-2C budget. Every gram, watt, dollar, and degree had to be justified, because the platform could not carry waste.
Software grew up without that discipline. It ran where size, power, cost, and cooling felt abstract and infinite. They never were, and in the AI era the bill has come due. Training and inference are now bounded by power delivery and heat, not by ideas.
JoulesPerBit applies SWaP-2C to computing itself. We make energy a measured, first-class quantity, and route every computation to its leanest path. The same budget that disciplines hardware, now disciplining bits.
less energy for AI and all computing, by 2030
See the budget at work
SWaP-C2 / SWaP-2C is a U.S. Department of Defense design principle: Size, Weight, Power, Cost, and Cooling.