What is the difference between a "rate" and a "speed" metric?
There are several different ways to measure computer performance. One way is to measure how fast the computer completes a single task; this is a speed measure. Another way is to measure how many tasks a computer can accomplish in a certain amount of time; this is called a throughput, capacity or rate measure.
The SPECspeed metrics (e.g., SPECint2006) are used for comparing the ability of a computer to complete single tasks.
The SPECrate metrics (e.g., SPECint_rate2006) measure the throughput or rate of a machine carrying out a number of tasks.
For the SPECrate metrics, multiple copies of the benchmarks are run simultaneously. Typically, the number of copies is the same as the number of CPUs on the machine, but this is not a requirement. For example, it would be perfectly acceptable to run 63 copies of the benchmarks on a 64-CPU machine (thereby leaving one CPU free to handle system overhead).
Note: a speed run which uses a parallelizing compiler to distribute one copy of a benchmark over multiple CPUs is still a speed run, and uses the SPECspeed metrics. You can identify such runs by the field "Auto Parallel".
原文：http://www.cnblogs.com/djiankuo/p/6230836.html