Sure, but avoiding CPU cache misses is hardly the only form of optimization. Some optimizations are blatantly obvious. As an example, there was some code I was working on that called the database every single time it was executed. The data it was pulling from the database got updated once a year, and the entire dataset could fit into about 4kb of memory. Caching it in memory was an obvious fix, and given how fast the rest of the code ran once it had this data it was basically a 500% speedup that anyone with half a brain could have roughly estimated.