Static Partitioning vs Dynamic Sharing of Resources in Simultaneous MultiThreading Microarchitectures

Simultaneous MultiThreading (SMT) achieves better system resource utilization and higher performance because it exploits ThreadLevel Parallelism (TLP) in addition to “conventional” Instruction-Level Parallelism (ILP). Theoretically, system resources in every pipeline stage of an SMT microarchitecture can be dynamically shared. However, in commercial applications, all the major queues are statically partitioned. From an implementation point of view, static partitioning of resources is easier to implement and has a lower hardware overhead and power consumption. In this paper, we strive to quantitatively determine the tradeoff between static partitioning and dynamic sharing. We find that static partitioning of either the instruction fetch queue (IFQ) or the reorder buffer (ROB) is not sufficient if implemented alone (3% and 9% performance decrease respectively in the worst case comparing with dynamic sharing), while statically partitioning both the IFQ and the ROB could achieve an ...

• Type: Conference
• Year: 2005
• Where: APPT
• Authors: Chen Liu, Jean-Luc Gaudiot
• Keywords: APPT 2005, Distributed And Parallel Programming, Dynamic Sharing, Performance, Static Partitioning