If there's a choice of spending X hours on performance tuning, fix the thing which gives the biggest win. There's no sense spending time saving 3us when you co

If there's a choice of spending X hours on performance tuning, fix the thing which gives the biggest win. There's no sense spending time saving 3us when you could have saved 3ms. And sure, once that's done, you can keep going to picoseconds, but there's only a limited number of application areas where that makes economic sense. It's also important to consider the entire system: you can optimize your code to the picosecond level, occupying the time of expensive engineers for months, but perhaps that $500k is better deployed on a PCIe5 bus, or a better Ethernet card, or a kernel-bypass stack, or even shorter network cables (every 300mm is a nanosecond, after all).