Transcript MilkyWay@Home and Volunteer Computing at RPI Travis Desell RCOS, April 23, 2010 MilkyWay@Home & Open Source Software • Milky Way Modeling Application • Multi-Platform Development: ATI, CUDA,

MilkyWay@Home and
Volunteer Computing at
RPI
Travis Desell
RCOS, April 23, 2010
MilkyWay@Home & Open Source Software
• Milky Way Modeling Application
• Multi-Platform Development: ATI,
CUDA, OpenCL, Windows, OS X,
Linux
• Generic Optimization Code (in the
works)
• BOINC - Berkeley Open Infrastructure
for Network Computing
MilkyWay@Home Statistics
• ~20,000 active users
• ~30,000 active hosts
• ~1.6 petaflops:
• most powerful BOINC project
• 3rd most powerful computing system
(behind Folding@Home and the
fastest supercomputer)
• most of this from GPU computing
Courtesy of http://www.boincstats.com
• First
GPU implementation was userMilkyWay@Home GPU Application
contributed
• Compared to 3.0Ghz AMD Phenom(tm)
II X4 940:
•
•
ATI HD5870 GPU - 109x speedup
NVidia GeForce GTX 285 GPU - 17x speedup
• Requires double-precision calculations:
•
NVidia GPUs have less double precision real estate
•
Application would be 6.2x faster on the ATI GPU,
7.8x faster on the NVidia GPU using single-precision
math
Travis Desell, Anthony Waters, Malik Magdon-Ismail, Boleslaw Szymanski, Carlos Varela, Matthew Newby, Heidi Newberg,
Andreas Przystawik and Dave Anderson. Accelerating the MilkyWay@Home volunteer computing project with GPUs. In the 8th
International Conference on Parallel Processing and Applied Mathematics (PPAM 2009), Wroclaw, Poland, September 2009.
The Sagittarius Dwarf Tidal Stream
• The Sagittarius Dwarf Galaxy is
merging with the Milky Way
• The dwarf is being tidally disrupted by
the Milky Way, creating long “tails.”
Image (below): David Martinez-Delgado (MPIA) & Gabriel Perez (IAC)
Image (above): [Ibata et al. 1997, AJ]
Mapping the Tidal Stream
will: information on matter
• Provide
distribution in Milky Way
• Provide constraints on Galactic
Halo
SLOAN Digital Sky Survey
Image: sdss.org
• 230+ million objects
• 8,400 square degrees in the sky
• Large percentage of north galactic cap
• Very little data in galactic plane (too much dust)
• Several hundred thousand stars
The Milky Way
Halo
Bulge
Thin Disk
Thick Disk
Data Wedge
Sun
Sagittarius Dwarf Galaxy
Tidal Stream
~30 kiloparsecs (100,000 light-years)
Image:
Matthew Newby
Sagittarius Stream Model
• Assume stream is a cylinder
• Radial drop-off given by a Gaussian
Distribution
• 2 background parameters (new
model has 4):
r0, q
• 6 parameters per stream:
ε, μ, r, θ, φ, σ
Background distribution:
• A single stream with the old model has an
8 dimensional search space
• Often fit multiple streams for search
spaces with more than 20 dimensions!
• [email protected]
BOINC
• [email protected]
• [email protected]
• Client Development:
•
Supporting different architectures
(GPUs)
•
Awarding fair “credit” for work done
• Server Development:
•
Scheduling
DNA@Home
• Find protein binding sites using
Gibbs sampling
• Use random walks (Markov
chains) which result in sites
distributed according to their
actual probability of being the
correct binding site
•
•
•
Initial sequences:
Mycobacterium tuberculosis
Yersinia pestis (cause of the
Bubonic plague)
Participate
• http://milkyway.cs.rpi.edu :
[email protected]
• http://dnahome.cs.rpi.edu :
[email protected]
• http://boinc.berkeley.edu