Aggressive compiler optimizations are not optional in many domains. One rule of thumb that a lot of people don't realize is that if you aren't maxing out your

Aggressive compiler optimizations are not optional in many domains. One rule of thumb that a lot of people don't realize is that if you aren't maxing out your sequential performance, your parallel multicore algorithm usually loses to an optimized sequential one. The reason is simple: parallelism introduces overhead, leading to guaranteed sublinear speedups. Compiler optimizations, on the other hand, frequently result in multiple factors of improvement.