Ehsan K. Ardestani

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Architects rely on simulation in their exploration of the design space. However, slow simulation speed caps their productivity and limits the depth of their exploration. Sampling has been a commonly used remedy. While sampling is shown to be an effective technique for single core processors, its application has been limited to simulation of multi-program,(More)
Temperature is a dominant factor in the performance, reliability, and leakage power consumption of modern processors. As a result, increasing numbers of researchers evaluate thermal characteristics in their proposals. In this paper, we measure a real processor focusing on its thermal characterization executing diverse workloads. Our results show that in(More)
With progressive generations and the ever-increasing promise of computing power, GPGPUs have been quickly growing in size, and at the same time, energy consumption has become a major bottleneck for them. The first level data cache and the scratchpad memory are critical to the performance of a GPGPU, but they are extremely energy inefficient due to the large(More)
High temperatures and non-uniform temperature distributions have become a serious concern since they limit both performance and reliability of Integrated Circuits (IC). With computer architect’s concern to position microarchitecture blocks in a processor, faster thermal models can be developed at the cost of hiding finer grain details such as circuit or(More)
High-temperature and temperature nonuniformity in high-performance integrated circuits (ICs) can significantly degrade chip performance and reliability. Thus, accurate temperature information is a critical factor in chip design and verification. Conventional volume grid-based techniques, such as finite-difference and finite-element methods (FEMs), are(More)
Studying the energy efficiency of large-scale computer systems requires models of the relationship between resource utilization and power consumption. Prior work on power modeling assumes that models built for a single node will scale to larger groups of machines. However, we find that inter-node variability in homogeneous clusters leads to substantially(More)
Thermal behavior of modern processors is a first-order design constraint. However, accurate estimation of thermal behavior is time consuming, and techniques for accelerating performance simulations often yield inaccurate results when directly applied to thermal simulation, or do not reduce the thermal computation at all. This paper is the first to propose(More)
With temperature being one of the main limiting factors in design of high performance processors, early evaluation of thermal effects in design stages is becoming a necessity. Floorplanning is an imperative step in the design process where thermal effects can be taken into account. This work studies a thermal-aware floorplanning scheme, with the goal of(More)
Power densities in modern processors induce thermal issues that limit performance. Power and thermal models add complexity to architectural simulators, limiting the depth of analysis. Prohibitive execution time overheads may be circumvented using sampling techniques. While these approaches work well when characterizing processor performance, they introduce(More)
Five percent to 25&percnt; of power could be wasted before it is delivered to the computational resources on a die, due to inefficiencies of voltage regulators and resistive loss. The power delivery could benefit if, at the same power, the delivered voltage increases and the current decreases. This article presents <i>CoreUnfolding</i>, a technique that(More)