Queue - May/June 2008

CAVEATS

Beowulf clusters have completely different networking economics. Render farms, materials simulation, and CFD fit beautifully on Beowulf clusters because there the cost of networking is very inexpensive: a GBps Ethernet fabric costs about $200 per port and delivers 50 MBps, so Beowulf networking costs are comparable to disk bandwidth costs— 10,000 times less than the price of Internet transports. That is why render farms and BLAST search engines are routinely built using Beowulf clusters. Beowulf clusters should not be confused with Internet-scale grid computations.

If telecom prices drop faster than Moore’s law, the analysis fails. If telecom prices drop slower than Moore’s law, the analysis becomes stronger. Most of the argument here pivots on the relatively high price of telecommunications. Over the past 40 years telecom prices have fallen much more slowly than any other information technology. If this situation changed, it could completely alter the arguments here, but there is no obvious sign of that occurring.

ACKNOWLEDGMENTS

Many people have helped me gather this information and present the results. Gordon Bell, Charlie Catmull, Pat Hanrahan, Gerd Heber, George Spix, Alex Szalay, and Dan Wertheimer helped me characterize various computations. Ian Foster and Andrew Herbert helped me present the argument more clearly.

REFERENCES

1. This article makes broad statements about the economics of computing. The numbers are fluid (costs change every day). They are approximate to within a factor of 3. For this specific fact: SETI@Home averaged 54 teraflops (floating-point operations/second) on 1/26/2003, handily beating the sum of the combined peak performance of the top four of the Top500 supercomputers registered at http://www.top500.org/ on that day.

2. Foster, I., Kesselman, C. (ed.). 1999. The Grid: Blueprint for a New Computing Infrastructure. San Francisco: Morgan Kaufmann.

3. See http://SkyQuery.net/ and http://TerrraService.net/. Each of these two Web sites acts as a portal to several SOAP Web services.

4. The hardware prices are typical of Web prices, the WAN price is typical of rates paid by large (many Gbps/month) Internet service providers. Hardware is depreciated over three years.

5. Ferreira, L. et. al. 2002. Introduction to Grid Computing with Globus. IBM Redbook series; http://ibm.com/redbooks.

6. Private communication from Gerd Heber, Cornell Theory Center, January 12, 2003.

7. Sterling, T., Salmon, J., Becker, D. J., Savarese, D. F. 1998. How to Build a Beowulf: A Guide to the Implementation and Application of PC Clusters. Cambridge: MIT Press.

8. Private communication from Ed Catmull, Pixar. April 2, 2003.

9. Altschul, S.F., Gish W., Miller W., Myers E. W., Lipman D. J. 1990. Basic local alignment search tool. Journal of Molecular Biology 215: 403-410; http://www.ncbi.nlm. nih.gov/BLAST/ and http://www.sun.com/products-n-solutions/edu/commofinter-est/compbio/pdf/parcel_blast.pdf for a large BLAST task.