Trying this program in a Virtualbox VM (no guest additions, 1 GB RAM) right now. It can basically do two things (aside from monitoring): "Clean memory" and "Clean file cache." The second is obvious enough, probably the rough equivalent of Linux's vm.drop_caches. That might improve performance, maybe, if Windows likes to swap out program memory to keep the filesystem cache big. (Note that a) I don't believe that is the default setting for desktop versions of Windows, and b) Linux is aggressive about maintaining large FS cache sizes, and that only causes bad performance on systems with < 1 GB of RAM in my experience.) The first though, I have no idea what on Earth it might be doing. It can't be that deep - the program is written in Visual Basic, I don't think it can even use the Native API! - but according to the task manager, whatever it's doing frees up a little memory... somehow. As for performance, I can't tell if it makes any difference at all. Next up, testing on a real laptop, and maybe some tracing with GDB. Edit: I'm a fool! Sysinternals Procmon should be able to show me what it's doing. Gimme a minute.