[dfcarney]

I was on the "silicon level debugging" team, which took test cases like this and boiled them down to x86, then through the CMS to p95 assembler, then down to the circuit and device level to figure out the speed paths. There were definitely some crazy issues we found. Honestly, I couldn't have done that job without relying on 80%+ of my undergrad courses (Computer Engineering @ Waterloo).

The issue I remember the most clearly was one that an engineer Simon Barrett discovered: a specific sequence of MMX instructions would cross-talk (and cause the occasional bit to flip) on two perpendicular busses in the pipeline when run at a specific voltage/frequency. It sounds simple enough, but imagine trying to figure that one out.