Comment by jodrellblank

And yet when Prof. Donald Knuth wrote that in 1974 paper[1] it was in this context:

> "The improvement in speed from Example 2 to Example 2a is only about 12%, and many people would pronounce that insignificant. The conventional wisdom shared by many of today's software engineers calls for ignoring efficiency in the small; but I believe this is simply an overreaction to the abuses they see being practiced by pennywise-and-pound-foolish programmers, who can't debug or maintain their "optimized" programs. In established engineering disciplines a 12% improvement, easily obtained, is never considered marginal"

also:

> "In the late 1960's we witnessed a "software crisis", which many people thought was paradoxical because programming was supposed to be so easy. As a result of the crisis, people are now beginning to renounce every feature of programming that can be considered guilty by virtue of its association with difficulties. Not only go to statements are being questioned; we also hear complaints about floating-point calculations, global variables, semaphores, pointer variables, and even assignment statements. Soon we might be restricted to only a dozen or so programs that are sufficiently simple to be allowable"

In a recent comment I mentioned a youtube interview with Rico Mariani, a performance engineer from Microsoft, and he said that he often got called into projects approaching their deadlines and not meeting their performance goals.

In one anecdote he spent a couple of hours with a team and showed how their design could never meat the goal even with the fastest disks, CPUs, memory, and network. And commented how strange it is if they had spent a day at the start of the project whiteboarding out the design against hardware specs at the start of the project - and avoided months of wasted effort - that would be called "premature optimization".

[1] https://dl.acm.org/doi/pdf/10.1145/356635.356640