Performance per watt
Beginner
How much useful work a chip does for each bit of electricity it uses. Higher is better, because electricity and cooling cost money.
Novice
Throughput divided by power, for example tokens per second per watt, which equals tokens per joule. It changes a lot depending on whose power you count: just the chip, the whole server, or the building too.
Expert
Specify the numerator (peak or delivered, which precision) and the denominator boundary (chip TDP, measured chip, wall power of the node, including switches, × PUE). MLPerf Power measures full-system wall power and reports samples per joule.
Explained in Comparing chips (Architectures).
See also: PUE (power usage effectiveness), TDP (thermal design power).