Modern processor systems are equipped with on-chip or on-board power controllers. In this paper, we examine the challenges and pitfalls in architecting such dynamic power management control systems. A key question that we pose is: How to ensure that such managed systems are “energy-secure” and how to pursue pre-silicon modeling to ensure such security? In other words, we address the robustness and security issues of such systems. We discuss new advances in energy-secure power management, starting with an assessment of potential vulnerabilities in systems that do not address such issues up front.

The design of high-performance servers has always been a challenging art. Now, server designers are being asked to explore a much larger design space as they consider multicore heterogeneous architecture and the limits of advancing silicon technology. Bringing automation to the early stages of design can enable more rapid and accurate trade-off analysis. In this paper, we introduce an Early Chip Planner which allows designers to rapidly analyze microarchitecture, physical and package design trade-offs for 2D and 3D VLSI chips and generates an attributed netlist to be carried on to the implementation stage. We also describe its use in planning a 3D special-purpose server processor.

This paper provides: 1) a very brief motivation and technological trend data to show why hard and soft errors are expected to be of increasing concern in the future; 2) a summary review of chip-level error tolerance practices today-with a brief reference to IBM's POWER6 and POWER7 designs; 3) open research challenges and current solution approaches of promise, based on published literature; and 4) concluding remarks.

Next generation system designs are challenged by multiple "walls": among them, the inter-related impediments offered by power dissipation limits and reliability are particularly difficult ones that all current chip/system design teams are grappling with. In this paper, we first describe the attendant challenges in integrated (multi-dimensional) pre-silicon modeling and the solution approaches being pursued. Later, we focus on leading edge solutions for power, thermal and failure-rate mitigation that have been proposed in our R&D work over the past decade.

Microarchitectural redundancy has been proposed as a means of improving chip lifetime reliability. It is typically used in a reactive way, allowing chips to maintain operability in the presence of failures by detecting and isolating, correcting, and/or replacing components on a first-come, first-served basis only after they become faulty. In this paper, we explore an alternative, more preferred method of exploiting microarchitectural redundancy to enhance chip lifetime reliability. In our proposed approach, redundancy is used proactively to allow non-faulty microarchitecture components to be temporarily deactivated, on a rotating basis, to suspend and/or recover from certain wearout effects. This approach improves chip lifetime reliability by warding off the onset of wearout failures as opposed to reacting to them posteriorly. Applied to on-chip cache SRAM for combating NBTI-induced wearout failure, our proactive wearout recovery approach increases lifetime reliability (measured in mean-time-to-failure) of the cache by about a factor of seven relative to no use of microarchitectural redundancy and a factor of five relative to conventional reactive use of redundancy having similar area overhead.

This paper tackles the issue of modeling chip lifetime reliability at the architecture level. We propose a new and robust structure-aware lifetime reliability model at the architecture-level, where devices only vulnerable to failure mechanisms and the effective stress condition of these devices are taken into account for the failure rate of microarchitecture structures. In addition, we present this reliability analysis framework based on a new concept, called the FIT of reference circuit or FORC, which allows architects to quantify failure rates without having to delve into low-level circuit- and technology-specific details of the implemented architecture. This is done through a onetime characterization of a reference circuit needed to quantify the reference FITs for each class of modeled failure mechanisms for a given technology and implementation style. With this new reliability modeling framework, architects are empowered to proceed with architecture-level reliability analysis independent of technological and environmental parameters.

Abstract : The performance of a PC cluster system is limited by the use of traditional communication protocols, such as TCP/IP, because these protocols are accompanied with significant software overheads. To overcome the problem, systems based on user-level message-passing interface without intervention of the kernel have been developed. VIA(Virtual Interface Architecture) is a widely adopted user-level message-passing interface which provides low latency and high bandwidth. In this paper, a software VIA system is implemented on an 8-node SCI(Scalable Coherent Interface) network based PC cluster. The system provides both message-passing and shared-memory programming environments and shows a maximum bandwidth of 84MB/s and a minimum latency of 8§A on application level. An average speed-up of 6.1 was obtained in executing the NAS parallel benchmark programs on the 8-node SCI-based PC cluster. The system also shows better performance in comparison with other comparable cluster systems in carrying out the parallel benchmark programs.