Cray Instability N. 1. A Shortcoming Of A Program Or Algorithm That Manifests Itself Only When A Large Problem Is Being Run On A Powerful Machine (see Cray).

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cray instability n.

1. A shortcoming of a program or
algorithm that manifests itself only when a large problem is being
run on a powerful machine (see cray). Generally more subtle
than bugs that can be detected in smaller problems running on a
workstation or mini. 2. More specifically, a shortcoming of
algorithms which are well behaved when run on gentle floating point
hardware (such as IEEE-standard or PDP-series machines) but which
break down badly when exposed to a Cray's unique `rounding'
rules.

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