2,128 research outputs found
QCD on \alpha-Clusters
It is shown that the 21264 Alpha processor can reach about 20% sustained
efficiency for the inversion of the Wilson-Dirac operator. Since fast ethernet
is not sufficient to get balancing between computation and communication on
reasonable lattice- and system-sizes, an interconnection using Myrinet is
discussed. We find a price/performance ratio comparable with state-of-the-art
SIMD-systems for lattice QCD.Comment: LATTICE99(machines), 3 page
Cost-Effective Clustering
Small Beowulf clusters can effectively serve as personal or group
supercomputers. In such an environment, a cluster can be optimally designed for
a specific problem (or a small set of codes). We discuss how theoretical
analysis of the code and benchmarking on similar hardware lead to optimal
systems.Comment: 7 pages, 2 figures (one in color). Color version of paper to be
published as part of proceedings of CCP2000 (Brisbane) in a special isssue of
Computer Physics Communication
The CMS Event Builder
The data acquisition system of the CMS experiment at the Large Hadron
Collider will employ an event builder which will combine data from about 500
data sources into full events at an aggregate throughput of 100 GByte/s.
Several architectures and switch technologies have been evaluated for the DAQ
Technical Design Report by measurements with test benches and by simulation.
This paper describes studies of an EVB test-bench based on 64 PCs acting as
data sources and data consumers and employing both Gigabit Ethernet and Myrinet
technologies as the interconnect. In the case of Ethernet, protocols based on
Layer-2 frames and on TCP/IP are evaluated. Results from ongoing studies,
including measurements on throughput and scaling are presented.
The architecture of the baseline CMS event builder will be outlined. The
event builder is organised into two stages with intelligent buffers in between.
The first stage contains 64 switches performing a first level of data
concentration by building super-fragments from fragments of 8 data sources. The
second stage combines the 64 super-fragments into full events. This
architecture allows installation of the second stage of the event builder in
steps, with the overall throughput scaling linearly with the number of switches
in the second stage. Possible implementations of the components of the event
builder are discussed and the expected performance of the full event builder is
outlined.Comment: Conference CHEP0
Recent development and perspectives of machines for lattice QCD
I highlight recent progress in cluster computer technology and assess status
and prospects of cluster computers for lattice QCD with respect to the
development of QCDOC and apeNEXT. Taking the LatFor test case, I specify a
512-processor QCD-cluster better than 1$/Mflops.Comment: 14 pages, 17 figures, Lattice2003(plenary
Lattice QCD Production on Commodity Clusters at Fermilab
We describe the construction and results to date of Fermilab's three
Myrinet-networked lattice QCD production clusters (an 80-node dual Pentium III
cluster, a 48-node dual Xeon cluster, and a 128-node dual Xeon cluster). We
examine a number of aspects of performance of the MILC lattice QCD code running
on these clusters.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics
(CHEP03), La Jolla, Ca, USA, March 2003, 6 pages, LaTeX, 8 eps figures. PSN
TUIT00
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