One of Joel Spolsky’s developers was complaining that compiling was getting slow (30 seconds) — leading to the usual sword fights in the hall — and wanted to spend a few weeks parallelizing the process to speed it up.
Joel decided against spending expensive developer time when he could instead buy new hardware. He decided to try solid state disks:
Boot time dropped from 2:11 to 0:34. That’s from a cold boot to launching Firefox and navigating to google.com. Launching 6 major applications went from about 20 seconds to about 10 seconds. In general, the fact that app launching is so much faster makes a huge difference and it was totally worth it. This little laptop is now the fastest computer I’ve ever used.
It didn’t improve compile time though.