552 PERFORMANCE
EXACT USE CHARACTERIZATION
If a machine has to be fully characterized before installation, there is no alternative to running the exact problem which will be run on the final system. This is the most expensive alternative to characterize performance and should be avoided because of the dynamic nature of use. Showing that an application yields a given performance on a particular machine is a weak guarantee of performance if any part of the problem changes.
Figure 2. Relative performance for various FORTRAN benchmarks run on VAX-11/780 and DECSYSTEM 2060.