There always are and always will be exceptions to every rule . . . but the IDE standard for max cable length is 18 inches. If you don't need more, then it is prudent to stay in the standard. Like others, I have used 24-inchers . . . but once I got into ATX cases and mobos, that was no longer necessary because the IDE ports on the mobo are on the upper right thus making for shorter runs. (I use only full tower cases.)