Speedup Techniques Utilized in Modern SAT Solvers

An Analysis in the MIRA Environment
  • Matthew D. T. Lewis
  • Tobias Schubert
  • Bernd W. Becker
Part of the Lecture Notes in Computer Science book series (LNCS, volume 3569)


This paper describes and compares features and techniques modern SAT solvers utilize to maximize performance. Here we focus on: Implication Queue Sorting (IQS) combined with Early Conflict Detection Based BCP (ECDB); and a modified decision heuristic based on the combination of Variable State Independent Decaying Sum (VSIDS), Berkmin, and Siege’s Variable Move to Front (VMTF). These features were implemented and compared within the framework of the MIRA SAT solver. The efficient implementation and analysis of these features are presented and the speedup and robustness each feature provides is demonstrated. Finally, with everything enabled (ECDB with IQS and advanced decision heuristics), MIRA was able to consistently outperform zChaff and even Forklift on the benchmarks provided, solving 37 out of 111 industrial benchmarks compared to zChaff’s 21 and Forklift’s 28.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2005

Authors and Affiliations

  • Matthew D. T. Lewis
    • 1
  • Tobias Schubert
    • 1
  • Bernd W. Becker
    • 1
  1. 1.Chair of Computer Architecture, Institute of Computer ScienceAlbert-Ludwigs-University of FreiburgGermany

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