If you work with numerical algorithms, understanding the architecture you’re running on can make a huge difference to performance. I once saw a colleague achie

If you work with numerical algorithms, understanding the architecture you’re running on can make a huge difference to performance. I once saw a colleague achieve something like a 30% speed-up just by swapping the inner and outer loops in an algorithm that worked on largish 2D arrays (matrices), just because the new nesting better matched the memory layout of the array and so made the hardware caches more effective.