Characterizing chip-multiprocessor variability-tolerance

Spatially-correlated intra-die process variations result in significant core-to-core frequency variations in chip-multiprocessors. An analytical model for frequency island chip-multiprocessor throughput is introduced. The improved variability-tolerance of FI-CMPs over their globally-clocked counterparts is quantified across a range of core counts and sizes under constant die area. The benefits are highest for designs consisting of many small cores, with the throughput of a globally-clocked design with 70 small cores increasing by 8.8% when per-core frequency islands are used. The smallcore FI-CMP also loses only 7.2% of its nominal performance to process variations, the least among any of the designs. Categories and Subject Descriptors C.4 [Performance of Systems]: Design studies General Terms Design, Performance Keywords Process variability, chip-multiprocessor, frequency islands

• Type: Conference
• Year: 2008
• Where: DAC
• Authors: Sebastian Herbert, Diana Marculescu
• Keywords: Core-to-core Frequency Variations, DAC 2008, Design Automation, Intra-die Process Variations, Per-core Frequency Islands