> You may be significantly underestimating your ability to get phenomenal gains from algorithmic improvements. Absolutely but often it's very hard to make thos

> You may be significantly underestimating your ability to get phenomenal gains from algorithmic improvements. Absolutely but often it's very hard to make those changes or those changes lead to a loss of accuracy, whereas compiling with -O3 is very easy and leads to no loss in accuracy (in the common case).