> WRT ultra low power computation and ignoring everything else, google TI MSP430 family or Microchips XLP (extreme low power) PIC series. Typical marketing figures are double/triple digit microamps of current per MHz of clock at a couple volts, so figure double/triple digit microwatts per MHz (and usually tops out at not many MHz),
There are plenty of manufacturers claiming now "ultra-low power" in various forms. EFM32, STM32L, Kinetis L-series come to mind now.
> which is of course fairly meaningless when compared across families because its a clock freq. Its rather important if a simple binary add takes one cycle at 300 uA/MHz vs 324 clock cycles at 30 uA/MHz, the better marketing figure does not necessarily provide best system performance figure of "actual real world work per microwatt"
Indeed. You also need to account for effects like "race to sleep" and the various special low-power operating modes. One recent interesting development in that area is "ULPBench" http://www.eembc.org/benchmark/ulp_sl.php which kinda promises to deliver a "work per microwatt" metric. Too bad it is so new that I haven't actually seen any credible results yet.
There are plenty of manufacturers claiming now "ultra-low power" in various forms. EFM32, STM32L, Kinetis L-series come to mind now.
> which is of course fairly meaningless when compared across families because its a clock freq. Its rather important if a simple binary add takes one cycle at 300 uA/MHz vs 324 clock cycles at 30 uA/MHz, the better marketing figure does not necessarily provide best system performance figure of "actual real world work per microwatt"
Indeed. You also need to account for effects like "race to sleep" and the various special low-power operating modes. One recent interesting development in that area is "ULPBench" http://www.eembc.org/benchmark/ulp_sl.php which kinda promises to deliver a "work per microwatt" metric. Too bad it is so new that I haven't actually seen any credible results yet.