Analysis and solutions to issue queue process variation

Niranjan Soundararajan, Aditya Yanamandra, Chrysostomos Nicopoulos, N. Vijaykrishnan, Anand Sivasubramaniam, Mary Jane Irwin

Research output: Contribution to conferencePaperpeer-review

4 Scopus citations


The last few years have witnessed an unprecedented explosion in transistor densities. Diminutive feature sizes have enabled microprocessor designers to break the billion-transistors per chip mark. However various new reliability challenges such as Process Variation (PV) have emerged that can no longer be ignored by chip designers. In this paper, we provide a comprehensive analysis of the effects of PV on the microprocessor's Issue Queue. Variations can slow down issue queue entries and result in as much as 20.5% performance degradation. To counter this, we look at different solutions that include Instruction Steering, Operand- and Port- switching mechanisms. Given that PV is non-deterministic at design-time, our mechanisms allow the fast and slow issue-queue entries to co-exist in turn enabling instruction dispatch, issue and forwarding to proceed with minimal stalls. Evaluation on a detailed simulation environment indicates that the proposed mechanisms can reduce performance degradation due to PV to a low 1.3%.

Original languageEnglish (US)
Number of pages11
StatePublished - 2008
Event2008 International Conference on Dependable Systems and Networks, DSN-2008 - Anchorage, AK, United States
Duration: Jun 24 2008Jun 27 2008


Other2008 International Conference on Dependable Systems and Networks, DSN-2008
Country/TerritoryUnited States
CityAnchorage, AK

All Science Journal Classification (ASJC) codes

  • Software
  • Hardware and Architecture
  • Computer Networks and Communications


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