The point is they need to be read once, and that one time takes more time and it is happening during the xml reading stage. Your CPU is fast, you will not notice that, we are talking a few milliseconds here, I doubt it adds up to even one second. There also is not that much more checking necessary, here are the steps I expect are additional - read MLF to determine order of reading actual definitions - read actual definitions - for each definition, check nothing whatsoever (over what CIV already checks) unless there are dependencies - if there are dependencies, check that all dependencies are met (i.e. all definitions it depends on have already been read) - if all have been read, everything is fine - if one or more definitions are missing, discard this definition That is it, actually that is next to nothing. It does not try to figure out a way to somehow merge all those definitions in the best possible way and juggle the dependencies while doing so, I agree that would be complex. If you want to see how much of it is due to your HD, just unpak my FPKs and move them out of assets, then you will see how much time it takes to load small art files compared to large FPKs imo the real problem would be the unpaked art, which is why I still pak it (while the WoC rule is not to do so as it then cannot be removed if you do not use it). As to the longer loading time, given that you load for a minute and play for an hour or more, the additional load time should not matter that much.