I upgraded the Gump machine yesterday from a Pentium II with 96 megs of RAM to a Pentium IV with 768 megs of RAM. Overall, the complete build cycle went from 4.5 hours to 1.5 hours. Not bad!
For those not familiar with Gump - Gump is a social experiment. The primary goal of Gump is to get diverse projects to communicate early and often about integration, dependencies, and versioning management. It generally enables integration issues to be identified within 24 hours of their introduction, making it considerably easier to determine the root cause and correct it before a product is released. At the moment, the current axis build fails due to a change in Ant. Because it was caught early, it will be corrected before Ant is released - meaning that developers who use released versions of Ant will never see this problem.
In fact, Peter Donald is experimenting with a proposal for a next version of Ant, and using the entire set of projects that Gump follows as backwards compatibility test.
For this to work, it relies on the responsiveness of developers.