[boyter]

In the case of Windows im sure they have a large test suite which runs benchmarks over tasks to weed out the non performant areas. Not only that in the later builds im sure its tested on thousands of systems to ensure that this code is weeded out in most cases.

Honestly, giving your developers a slow machine to "encourage" them to write faster code is a fallacy. The average user is not running multiple databases, multiple IDE's, debuggers, editors, multiple browsers, help documents and all the other programs they require to get stuff done. By all means make the test machine match what the users have but invest (yes it is an investment) in a fast machine for your developers.

If nothing else it will make them feel appreciated which will return more then the $1000 odd it will cost to spec their machine up from your users base model.