Sebastian Herbert

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Fine-grained dynamic voltage/frequency scaling (DVFS) demonstrates great promise for improving the energy-efficiency of chip-multiprocessors (CMPs), which have emerged as a popular way for designers to exploit growing transistor budgets. We examine the tradeoffs involved in the choice of both DVFS control scheme and method by which the processor is(More)
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(More)
Fine-grained dynamic voltage/frequency scaling (DVFS) is an important tool in managing the balance between power and performance in chip-multiprocessors. Although manufacturing process variations are giving rise to significant core-to-core variations in power and performance, traditional DVFS controllers are unaware of these variations.
Adaptive body biasing is a promising technique for addressing increasing process variability, but it also provides new opportunities for reducing power when combined with dynamic voltage/frequency scaling. Limitations of existing ABB/DVFS proposals are explored, and a new scheme, test-time voltage selection (TTVS), is presented. By delaying the mapping(More)
This paper presents methods for addressing two sources of variability in the context of microprocessors within-die process variability and dynamic thermal variability and shows the improvements in performance and energy efficiency obtained by applying them to a globally asynchronous, locally synchronous (GALS) microprocessor design. The GALS design style(More)
Emerging multi-core platforms are increasingly impacted by the manufacturing process variations that introduce core-to-core and chip-to-chip differences in their power and performance characteristics. This can result in unacceptable yield loss since a large fraction of manufactured parts may not meet the design specifications. In this work, we present some(More)
Semiconductor manufacturing process variations are worsening with continued reduction in transistor feature sizes. However, technology scaling is the engine driving the semiconductor industry and must continue. When variations worsen to the point that they can no longer be addressed solely at the device and circuit levels, the next logical step is to(More)
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