Is the Internet Green?

Research at the University of Melbourne in Australia, presented to the Symposium on Sustainability of the Internet and ICT, claims that a surge in energy consumption caused by the increased adoption of broadband will continue to slow the Internet. The study is the first to model Internet power consumption due to services like video on demand (VOD) and will enable MU researchers to identify the major contributors to Internet power consumption as the adoption of broadband services grows in the coming years.

Worldwide Supercomputer Ratings

Interesting visualization of worldwide supercomputer performance. These Flash bubble-charts seem to be de rigueur for the NYT now. Bubble diameters are proportional to their TFLOPS rating and the location of each bubble cluster is topologically correct with respect to geographical location, but not by Euclidean distance; which is probably why it wasn't superimposed on a map.

The breakdown of these top-100 machines by processor family (not shown there) looks like this:

1. Intel: 75.6%
   
2. IBM: 12%
   
3. AMD: 12%
   
4. NEC: 0.2%
   
5. SPARC: 0.2%

However, the number 1 machine (at 1.1 petaFLOPs) is based on the IBM Cell processor.

What the Harmonic Mean Means

As I discuss in Chapter 1 of The Practical Performance Analyst, time is the fundamental performance metric. Computer system performance metrics are therefore either direct measures of time, e.g, seconds, hours, minutes, or they are rates. All rate metrics have their units of time in the denominator, e.g., GB/s, MIPS, TPS, IOPS.

A conceptual difficulty can arise when we try to summarize a set of performance numbers as a single number; especially if they're rates.