85,216 research outputs found
Power aware early design stage hardware software co-optimization
Co-optimizing hardware and software can lead to substantial performance and energy benefits, and is becoming an increasingly important design paradigm. In scientific computing, power constraints increasingly necessitate the return to specialized chips such as Intel’s MIC or IBM’s Blue-Gene architectures. To enable hardware/software co-design in early stages of the design cycle, we propose a simulation infrastructure methodology by combining high-abstraction performance simulation using Sniper with power modeling using McPAT and custom DRAM power models. Sniper/McPAT is fast — simulation speed is around 2 MIPS on an 8-core host machine — because it uses analytical modeling to abstract away core performance during multi-core simulation. We demonstrate Sniper/McPAT’s accuracy through validation against real hardware; we report average performance and power prediction errors of 22.1% and 8.3%, respectively, for a set of SPEComp benchmarks
Baseband analog front-end and digital back-end for reconfigurable multi-standard terminals
Multimedia applications are driving wireless network operators to add high-speed data services such as Edge (E-GPRS), WCDMA (UMTS) and WLAN (IEEE 802.11a,b,g) to the existing GSM network. This creates the need for multi-mode cellular handsets that support a wide range of communication standards, each with a different RF frequency, signal bandwidth, modulation scheme etc. This in turn generates several design challenges for the analog and digital building blocks of the physical layer. In addition to the above-mentioned protocols, mobile devices often include Bluetooth, GPS, FM-radio and TV services that can work concurrently with data and voice communication. Multi-mode, multi-band, and multi-standard mobile terminals must satisfy all these different requirements. Sharing and/or switching transceiver building blocks in these handsets is mandatory in order to extend battery life and/or reduce cost. Only adaptive circuits that are able to reconfigure themselves within the handover time can meet the design requirements of a single receiver or transmitter covering all the different standards while ensuring seamless inter-interoperability. This paper presents analog and digital base-band circuits that are able to support GSM (with Edge), WCDMA (UMTS), WLAN and Bluetooth using reconfigurable building blocks. The blocks can trade off power consumption for performance on the fly, depending on the standard to be supported and the required QoS (Quality of Service) leve
The E-ELT Multi-Object Spectrograph: latest news from MOSAIC
There are 8000 galaxies, including 1600 at z larger than 1.6, which could be
simultaneously observed in an E-ELT field of view of 40 sq. arcmin. A
considerable fraction of astrophysical discoveries require large statistical
samples, which can only be obtained with multi-object spectrographs (MOS).
MOSAIC will provide a vast discovery space, enabled by a multiplex of 200 and
spectral resolving powers of R=5000 and 20000. MOSAIC will also offer the
unique capability of more than 10 "high-definition" (multi-object adaptive
optics, MOAO) integral-field units, optimised to investigate the physics of the
sources of reionization. The combination of these modes will make MOSAIC the
world-leading MOS facility, contributing to all fields of contemporary
astronomy, from extra-solar planets, to the study of the halo of the Milky Way
and its satellites, and from resolved stellar populations in nearby galaxies
out to observations of the earliest "first-light" structures in the Universe.
It will also study the distribution of the dark and ordinary matter at all
scales and epochs of the Universe. Recent studies of critical technical issues
such as sky-background subtraction and MOAO have demonstrated that such a MOS
is feasible with state-of-the-art technology and techniques. Current studies of
the MOSAIC team include further trade-offs on the wavelength coverage, a
solution for compensating for the non-telecentric new design of the telescope,
and tests of the saturation of skylines especially in the near-IR bands. In the
2020s the E-ELT will become the world's largest optical/IR telescope, and we
argue that it has to be equipped as soon as possible with a MOS to provide the
most efficient, and likely the best way to follow-up on James Webb Space
Telescope (JWST) observations.Comment: 10 pages, 3 Figures, in Ground-based and Airborne Instrumentation for
Astronomy VI, 2016, Proc. SPI
Using fast and accurate simulation to explore hardware/software trade-offs in the multi-core era
Writing well-performing parallel programs is challenging in the multi-core processor era. In addition to achieving good per-thread performance, which in itself is a balancing act between instruction-level parallelism, pipeline effects and good memory performance, multi-threaded programs complicate matters even further. These programs require synchronization, and are affected by the interactions between threads through sharing of both processor resources and the cache hierarchy.
At the Intel Exascience Lab, we are developing an architectural simulator called Sniper for simulating future exascale-era multi-core processors. Its goal is twofold: Sniper should assist hardware designers to make design decisions, while simultaneously providing software designers with a tool to gain insight into the behavior of their algorithms and allow for optimization. By taking architectural features into account, our simulator can provide more insight into parallel programs than what can be obtained from existing performance analysis tools. This unique combination of hardware simulator and software performance analysis tool makes Sniper a useful tool for a simultaneous exploration of the hardware and software design space for future high-performance multi-core systems
Cost-effective aperture arrays for SKA Phase 1: single or dual-band?
An important design decision for the first phase of the Square Kilometre
Array is whether the low frequency component (SKA1-low) should be implemented
as a single or dual-band aperture array; that is, using one or two antenna
element designs to observe the 70-450 MHz frequency band. This memo uses an
elementary parametric analysis to make a quantitative, first-order cost
comparison of representative implementations of a single and dual-band system,
chosen for comparable performance characteristics. A direct comparison of the
SKA1-low station costs reveals that those costs are similar, although the
uncertainties are high. The cost impact on the broader telescope system varies:
the deployment and site preparation costs are higher for the dual-band array,
but the digital signal processing costs are higher for the single-band array.
This parametric analysis also shows that a first stage of analogue tile
beamforming, as opposed to only station-level, all-digital beamforming, has the
potential to significantly reduce the cost of the SKA1-low stations. However,
tile beamforming can limit flexibility and performance, principally in terms of
reducing accessible field of view. We examine the cost impacts in the context
of scientific performance, for which the spacing and intra-station layout of
the antenna elements are important derived parameters. We discuss the
implications of the many possible intra-station signal transport and processing
architectures and consider areas where future work could improve the accuracy
of SKA1-low costing.Comment: 64 pages, 23 figures, submitted to the SKA Memo serie
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