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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)
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)
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)
This paper explores the trade-offs between on-loaded versus offloaded network stack processing for systems with varying CPU frequencies. This study explores the differences of onload and offload using experiments run at different DVFS settings to change the frequency, while measuring performance and power. This allows for a quantitative comparison of the(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)
High-performance sockets implementations such as the Sockets Direct Protocol (SDP) have traditionally showed major performance advantages compared to the TCP/IP stack over InfiniBand (IPoIB). These stacks bypass the kernel-based TCP/IP and take advantage of network hardware features, providing enhanced performance. SDP has excellent performance but limited(More)