NUCA caches are large L2 on-chip cache memories characterized by multi-bank partitioning and designed to hide wire delay effects. They exhibit high hit rates while keeping access latency low. Proposed designs for such caches are Static NUCA, in which data are statically allocated to the cache banks, and Dynamic NUCA, in which data may reside in different banks, and a migration mechanism is introduced to better tolerate wire delay effects. The two architectures permit to achieve different performances by acting on architectural parameters and data management policies, at the cost of different balances between static and dynamic power consumption and energy dissipation. In this work, we propose preliminary results of the characterization of such balances, by presenting an evaluation of performance and energy consumption of conventional UCAs, and Static and Dynamic NUCA caches. All the considered caches architectures are equal sized and they are supposed to be used in an aggressive high frequency system running some applications from the SPEC CPU2000 and the NAS Parallel Benchmarks suites. The experimental results obtained indicate that, although the migration of data contributes to increase the dynamic energy consumption in Dynamic NUCA caches, the higher IPC achieved permits to save static energy, which dominates the power/energy balance in all the considered architectures. As a consequence, such results would designate NUCA caches as the most performing and energy saving architectures. Besides, according to the obtained results, future power improvements for NUCA caches should concentrate on static energy, while, for the dynamic energy, the on-chip network is the most critical element. Migration of data is acceptable, since it has a positive impact on performance, and the increased dynamic energy is overwhelmed by the static energy savings resulting from the shorter execution time. In order to give a general validity to such statements, we need to explore more design space points for each architecture (by varying the running clock rate and other design parameters) and to evaluate them considering a larger set of benchmark
In the case of the glass tube for pharmaceutical applications, high‐quality defect detection is made via inspection systems based on image processing. Such processing must be fast enough to guarantee real‐time inspection and to meet the increasing rate and quality required by the market. Defect detection is complex due to specific problems of the production process: vibration, rotation and irregularity of the tube. All these aspects prevent the efficient use of known techniques. The authors present an algorithm that decreases the processing time of the defect detection phase. The algorithm is based on a moving average filter working at row level, that allows to minimize the effects of rotation, vibration, and irregularity of the tube. Luminosity variations due to the tube curvature are cut by the filter and a threshold algorithm can be applied. They made the evaluation considering different solutions taken from literature. The algorithm outperforms, in processing time, all these solutions with increased accuracy. Experimental measures show that the algorithm achieves a throughput gain of 2.6 times with respect to Canny. They develop also a methodology to get the best values for the algorithm parameters directly at the factory, during the change of production batches.
1 January 2010 in International Journal of High Performance Systems Architecture
Non-uniform cache architecture (NUCA) aims to limit the wire-delay problem typical of large on-chip last level caches: by partitioning a large cache into several banks, with the latency of each one depending on its physical location and by employing a scalable on-chip network to interconnect the banks with the cache controller, the average access latency can be reduced with respect to a traditional cache. The addition of a migration mechanism to move the most frequently accessed data towards the cache controller (D-NUCA) further improves the average access latency. In this work we propose a last-level cache design, based on the D-NUCA scheme, which is able to significantly limit its static power consumption by dynamically adapting to the needs of the running application: the way adaptable D-NUCA cache. This design leads to a fast and power-efficient memory hierarchy with an average reduction by 31.2% in energy-delay product (EDP) with respect to a traditional D-NUCA. We propose and discuss a methodology for tuning the intrinsic parameters of our design and investigate the adoption of the way adaptable D-NUCA scheme as a shared L2 cache in a chip multiprocessor (CMP) system (24% reduction of EDP).
This paper shows how GSR signals can be related to traditional usability metrics. The test case is an e-government Website, enriched with an animated face to help users' navigation. First, we present the results on the effects of the talking face, which have been assessed with traditional usability metrics in a within- group experiment. Then, we show how such traditional analyses have correspondence in GSR signals. As the GSR signal is very subjective, its log data must be analyzed with care, in order to have significant and robust results. Applying a differential analysis, the GSR traces supported some findings obtained with traditional usability metrics.