It's All About Speed

Every cluster builder wants to know how fast his or her computer is. After all, speed is the primary reason to build a Linux cluster -- aside from the gains in data capacity and resource redundancy. But how do you measure speed? CPU clock speed is one thing, but using those cycles to actually get work done is quite another. And in a cluster, the network connections between nodes can quickly become a crippling bottleneck.

Linpack Benchmark

High-Performance Linpack (HPL) is a free implementation of the Linpack benchmark for distributed-memory computers. It solves a random, dense linear system of equations in double precision arithmetic in parallel. Developed at the Innovative Computing Laboratory at the University of Tennessee, HPL provides a testing and timing program to quantify the accuracy of the obtained solution and the time it took to compute it.

Top Computers of the World

Released twice each year, the "Top 500 List of Supercomputing Sites" (http://www.top500.org) tracks the world's most powerful computer systems, where performance on the Linpack benchmark is used to rank the systems. In each edition of the list, released in June or November, does contain every kind of computer, from the most expensive commercial supercomputers to self-made Linux clusters.