Homework 0

Yatish Patel - Brief Bio

I'm currently a 3rd year CS major specializing in computer architecture. My research intrests includes looking at possible scalable,silicon based computer architectures for quantum computers. As far as what I want to get out of this class...I simply want to learn more about parallel applications.

Application problem: Earthquake simulation [1]

• What is the scientific or engineering problem being solved?

The researchers are interested in modelling seismic wave propagation resulting from large earthquakes. They are interested in the three-demensional seismic wave-speed structure of the Earth, the rupture process during a large earthquake, and proagation of resulting seismic waves. They want to use these results to help map the structure of the Earth's interior.

• How well did the application achieve its scientific objective? Are simulation results compared to physical results?

The simulation results are compared to physical results. The detailed version of the simulations yield very accurate results as shown in the figure below.


• What parallel platform has the application targetted? (distributed v. shared memory, vector, etc.) What tools were used to build the application? (languages, libraries)
• If the application is run on a major supercomputer, where does that computer rank on the Top 500 list?

The application is run on 1944 processors of the Earth Simulator which is currently ranked number one on the Top 500 list.

• How well did the application perform? How does this compare to the platform's best possible performance?

The application used 38% of the Earth Simulator and was able to reach a performance of 5 teraflops (30% of the peak performance).

• Does the application "scale" to large problems on many processors? If you believe it has not, what bottlenecks may have limited its performance?

References

1. Dimitri Komatitsch, Seiji Tsuboi, Chen Ji and Jeroen Trompi (2003). A 14.6 billion degrees of freedom, 5 teraflops, 2.5 terabyte earthquake simulation on th e Earth Simulator [PDF]