I happen to work in the computational fluid dynamics department and I happen to have coded in the video game industry (optimized 3D engines). So I do know when

I happen to work in the computational fluid dynamics department and I happen to have coded in the video game industry (optimized 3D engines). So I do know when optimizing is necessary. It's just that most of the time, for my computation, just waiting a few hours for a one-shot computation is much more effcient than spending 2 days optimizing it so that it runs in 20 minutes. But I admit my parent message was not quite clear on the context in which I was thinking :-)