This is the recording of my talk at IPSN 2010 of the "Best Paper Award" winning publication. Following is the abstract:

We present Virtual High-resolution Time (VHT), a power-proportional
time-keeping service that offers a baseline power draw of a low-speed
clock (e.g. 32~kHz crystal), but provides the time resolution that
only a higher frequency clock could offer (e.g. 8~MHz crystal), and
scales essentially linearly with access (i.e. the ``reading'' and
``writing'' of the clock). We achieve this performance by revisiting
a basic assumption in the design of time-keeping systems -- that to
achieve a given time-stamping resolution, a free-running timebase of
equivalent frequency is needed. We show that this assumption is false
and argue that the dependence is not on usage (i.e. whether on or off)
but rather on access (i.e. reading and writing). Therefore, it is
possible to duty cycle the free-running timebase itself, and augment
it with a lower-frequency, temperature-compensated one, which achieves
comparable resolution, at a fraction of the power, for typical
workloads. The key technical challenge lies in duty cycling the fast
clock and synchronizing the fast and slow clocks. To assess the
viability of the approach, we explore how VHT could be implemented on
several different platform architectures, and to study the
power/performance tradeoff, we characterize VHT on one particular
architecture in detail. Our results show power-proportional operation
with a 10x improvement in average power and a synchronization
accuracy exceeding 1 us at duty cycles below 0.1%.

Loading more stuff…

Hmm…it looks like things are taking a while to load. Try again?

Loading videos…