Ryan E. Grant

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Recently, under a fixed power budget, asymmetric multiprocessors (AMP) have been proposed to improve the performance of multi-threaded applications compared to symmetric multiprocessors. An AMP is a multiprocessor system in which its processors are not operating at the same frequency. Power consumption has become an important design constraint in servers(More)
The U. S. Department of Energy has identified resilience and energy consumption as key challenges for future extreme-scale systems. All checkpoint/restart methods require I/O to local or remote storage. Efforts are under way to minimize the amount of data movement and increase scalability. Nevertheless, the energy consumed by fault resilience methods will(More)
Hybrid chip multithreaded SMPs present new challenges as well as new opportunities to maximize performance. Our intention is to discover the optimal operating configuration of such systems for scientific applications and to identify the shared resources that might become a bottleneck to performance under the different hardware configurations. This knowledge(More)
Simultaneous Multithreading (SMT) is a technique that allows multiple independent threads to execute different instructions each cycle. Hyper-Threading (HT) is an implementation of SMT available on recent processors from Intel. Naturally, Multi-threaded applications are very suitable for SMT systems. However, HT due to extensive resource sharing may not(More)
iWARP represents the leading edge of high performance Ethernet technologies. By utilizing an asynchronous communication model, iWARP brings the advantages of OS bypass and RDMA technology to Ethernet. The current specification of iWARP is only defined over connection-oriented transports such as TCP. The memory r equirements of many connections along with(More)
iWARP is a state of the art high-speed connection-based RDMA networking technology for Ethernet networks to provide InfiniBand-like zero-copy and one-sided communication capabilities over Ethernet. Despite the benefits offered by iWARP, many data center and web-based applications, such as stock-market trading and media-streaming applications, that rely on(More)
The introduction of quality of service (QoS) features for socket-based communication over InfiniBand networks provides the opportunity to enact service differentiation for traditional socket-based applications over high performance networks for the first time. The effectiveness of such techniques in providing control over the quality of service that(More)
Advances in node-level architecture and interconnect technology needed to reach extreme scale necessitate a reevaluation of long-standing models of computation, in particular bulk synchronous processing. The end of Dennard-scaling and subsequent increases in CPU core counts each successive generation of general purpose processor has made the ability to(More)