And of course the caching algoritms of your hard-drive and OS will have a big influence as well. If the file is small enough to be read in one go, slurping will not have any big added speed-benefit, but will increase memory load.

And if the file is rather large, it may crowd out other items in your cache and slow down other programs: TANSTAAFL, as Heinlein said.

CountZero

"If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law