Chasing the Energizer Bunny

1
Chasing the Energizer Bunny

• Ben Zorn
• Microsoft Research

2
Form Factor Fuels Innovation

• Form factor more important now than CPU
  performance
• Power efficiency and form factor linked
• No one talks about the power wall
• Battery technology not improving exponentially
• Entire problem domains revolve around power
  performance
• Personal devices exploding
• Cell phones, Ipod, PSP, mp3 players
• Devices fundamentally change how we live, work
• Ipod Moms, Bens audible books

3
Prediction Multi-core follows Power

• My prediction
• Greatest uptake in multi-core designs will be in
  systems that dont have as much legacy code
• Opportunities for 10-100x power reductions are
  available, under-investigated
• Domain-specific applications of multi-core easier
  to bring to market (voice recognition, vision,
  etc.)
• The revolution has already begun.

4
Implied Research Agenda?

• Complexity increases power consumption (David
  Sehr)
• Out-of-order execution inefficient, out of favor
• Incidentally, also increases security risk
• General-purpose HW less power efficient than
  special-purpose
• Hiding latency the best use of all those
  transistors (in caches)?
• A return to RISC-style HW/SW design?
• Every field rediscovers simplicity on
  predictable schedule

5
Relation to MSP?

• Performance should include power efficiency
• The power cost of latency reduction and/or
  implementation complexity should be quantified
• More papers in MSP about power
• Better frameworks for evaluating power efficiency
• More evaluations of designs in context of actual
  systems (not SPEC)