Top 5 Reasons Reliability is the Biggest Fallacy in Computer Architecture Research

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Top 5 ReasonsReliability is the Biggest Fallacy
in Computer Architecture Research

• Scott Mahlke
• University of Michigan

Thanks to Jason Blome, Shuguang Feng, and
Shantanu Gupta for putting their research on
reliable systems on hold to help with this
presentation.
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Disclaimer
Still a need for high reliability designs for
mission critical systems

• Space shuttle, airplanes, etc.
• Cost is not an issue use high degrees of
  redundancy

I would like to convince you reliability is a
fallacy for mainstream computer systems used in
consumer/business electronics
The speaker may not agree with this position
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Reason 1 Its the Software, Stupid!

• Mature OS can have an MTTF measured in months,
  while newer OS may crash every few days. Peter
  Chen Reliability Hierarchies, 1999 HOT OS.
• Sources 1 www.nstl.com 2 A system-level
  approach for memory robustness, ICMTD05 3
  Lifetime Reliability Towards an architectural
  solution, IEEE Micro 2005 4 www.calce.umd.edu

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Hmm My ATM Does Not Work
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Reason 2 Disposable Electronics

• The average working life of a mobile phone is 7
  years, but the average consumer changes their
  mobile every 11 months.

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PCs/Laptops Not Far Behind

• Take-away something.
• http/ieeexplore.ieee.org/iel5/9100/28876/01299720
  .pdf

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Reason 3 A Transient Fault is About As Likely As

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Reason 4 Does Anyone Care?
Which is flawed?

• Can a human identify errors in video, images, or
  sound?
• Glitches are accepted by the consumer (dropped
  cell calls)
• Natural redundancy and resiliency in software

100 reliable operation of hardware is not
important or worth extra cost in many situations
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Reason 5 This Problem is Better Solved Closer to
the Circuit Level
Electromigration in copper

• Lower overhead
• Many designs benefit
• In-situ solutions naturally handle variation

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Some Hope?
What if we assume reliability is a looming
problem. Then we need solutions that are

• Low overhead, high rate of return
  solutions Joint circuit/architectural
  techniques
• Domain specific solutions know thy customer
• Reliability features provide other
  benefits Its not just a tax

The bottom line