10x10: A General-purpose Architectural Approach to Heterogeneity
and Energy Efficiency
Procedia Comput. Sci., 4 (0):
1987--1996 (2011)Abstract
Two decades of microprocessor architecture driven by quantitative
90/10 optimization has delivered an extraordinary 1000-fold
improvement in microprocessor performance, enabled by transistor
scaling which improved density, speed, and energy. Recent
generations of technology have produced limited benefits in
transistor speed and power, so as a result the industry has
turned to multicore parallelism for performance scaling.
Long-range studies 1,2 indicate that radical approaches are
needed in the coming decade -- extreme parallelism,
near-threshold voltage scaling (and resulting poor single-thread
performance), and tolerance of extreme variability -- are
required to maximize energy efficiency and compute density. These
changes create major new challenges in architecture and software.
As a result, the performance and energy-efficiency advantages of
heterogeneous architectures are increasingly attractive. However,
computing has lacked an optimization paradigm in which to
systematically analyze, assess, and implement heterogeneous
computing. We propose a new paradigm, ``10x10'', which clusters
applications into a set of less frequent cases (ie. 10\% cases),
and creates customized architecture, implementation, and software
solutions for each of these clusters, achieving significantly
better energy efficiency and performance. We call this approach
``10x10'' because the approach is exemplified by optimizing ten
different 10\% cases, reflecting a shift away from the 90/10
optimization paradigm framed by Amdahl's law 3. We describe the
10x10 approach, explain how it solves the major obstacles to
widespread adoption of heterogeneous architectures, and present a
preliminary 10x10 clustering, strawman architecture, and software
tool chain approach.
