Understanding the energy efficiency of simultaneous multithreading

ABSTRACT

Simultaneous multithreading (SMT) has proven to be an effective method of increasing the performance of microprocessors by extracting additional instruction-level parallelism from multiple threads. In current microprocessor designs, power-efficiency is of critical importance, and we present modeling extensions to an architectural simulator to allow us to study the power-performance efficiency of SMT. After a thorough design space exploration we find that SMT can provide a performance speedup of nearly 20% for a wide range of applications with a power overhead of roughly 24%. Thus, SMT can provide a substantial benefit for energy-efficiency metrics such as ED². We also explore the underlying reasons for the power uplift, analyze the impact of leakage-sensitive process technologies, and discuss our model validation strategy.

REFERENCES

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INDEX TERMS

Primary Classification:
  C. Computer Systems Organization
  C.1 PROCESSOR ARCHITECTURES

Additional Classification:
  B. Hardware
  B.0 GENERAL

Keywords:
multithreading