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WP34s Power Proc-Speed Performance
02-13-2015, 11:49 PM
Post: #8
RE: WP34s Power Proc-Speed Performance
(02-13-2015 11:35 PM)matthiaspaul Wrote:  
(02-13-2015 10:54 PM)MarkHaysHarris777 Wrote:  So, the lesson here is that you will literally cut your power consumption in half ( delta of -53.8 % <decrease> ) by setting your proc frequency to 'SLOW' prior to long loops, data transfers, or updates.
But you basically won't gain anything in regard to the needed energy, since you need twice the time (ignoring some chemical processes inside the battery, which differ depending on the load)... ;-)

FWIW the observed trade-off of speed versus current is what can be expected from a processor manufactured in CMOS (complementary metal-oxide semiconductor) technology. One characteristic of this technology is that a cell consisting of two complementary MOSFETs draws measureable power only in state transitions, whereas in the static phases between these transitions, either one or the other transistor is always off (and the complementary one always on, respectively), so that no current can flow from supply to ground except for in those moments of state transition. So, the power consumption is a linear function of clock frequency - down to virtually zero when the clock is off.

Greetings,

Matthias

What was it that the 'BORG' said to Data, "... you think so three dimensionally!".

The gain is not in energy over time (which can neither be created nor destroyed, only transferred); rather, the gain is in performance and critical load balancing. Its better to have a long loop running x2 with a lower voltage drop because it is more likely that the voltage drop will remain above critical threshold and the damn thing won't shut down mid process! By the way, if that happens, it is possible to lose everything in the system! If we keep the current low, the voltage hi, and the process stretched out over some time we get better performance and avoid the power-off-in-the-middle-glitch.

Also, coin cells will recover better from lower current over time, than huge current draws over short time. The power consumption over time will be the same regardless, but the overall performance of the system will be better at slower proc frequency.

Cheers,
marcus
Smile

Kind regards,
marcus
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RE: WP34s Power Proc-Speed Performance - MarkHaysHarris777 - 02-13-2015 11:49 PM



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