Performance limitations in wide superscalar processors

Scope and Method of Study:Superscalar processors with wide instruction fetch only results in diminishing performance returns. The aim of this research to find what causes these limitations. In addition, a new cycle-accurate computer architecture simulator - AbaKus - is developed to study and evaluate the performance of the architecture designs.Findings and Conclusions:Eager-Based executions and their designs are tested to overcome the effects of low-accuracy of branch prediction on 38% of the conditional branch instructions. An improvement IPC of 27% on average is shown. However, confidence estimators need improvement on its design logic as they prove critical on the performance of eager-based executions. In addition, the limitation of compilers to extract ILP from the benchmark programs leads to a severe restriction on performance of Superscalar architectures due to data dependencies