Two interesting thoughts about tests:
We hired a new developer. He didn't have a strong background in what we do, but he has solid skills and an excellent academic background. In working with him yesterday, I was showing him the test suite and he mentioned that he heard it was slow. He tossed out various ideas to speed it up, but there were problems with many of them. Then he mentioned a ramdisk.
Today we mounted a ram disk and pointed a test mysql instance at it. Our "fast" set of tests takes about 57 minutes to run. Now it takes 31. I just reniced it and started it again.
If this proves workable, we might even set up a dedicated test server just for this. If we lose power, we lose the data, but who cares? It's just for testing and we can bring it up again.
Thinking about this raises an obvious question: what would happen if we put our production database on a solid state drive? Their prices are dropping rapidly and we could get a huge performance boost on our production app with with no architectural changes.