Originally posted by: Maezr
that certainly does make more sense, thanks... can't believe they'd name it that.
There
is a little bit of logic behind it -- even if your swapfile is disabled, you are still using the virtual memory system, and Windows refers to the main VM space as the "page file" or "paging area". Just saying "memory usage" itself is a little misleading, because then it's not clear if you mean:
1) Physical RAM that is in use (ie, "Total" physical memory minus "Available" physical memory)
2) The portion of the 'real' swap space (on disk) that is in use (not visible in Task Manager, but possibly through Performance Monitor as mentioned in the link above)
3) The amount of 'virtual' space that has been allocated by programs (what XP calls "PF usage")
4) The amount of 'virtual' space that really is actually backed by the pagefile (this is the "commit charge total" and is what people usually mean when they talk about "memory usage")
The whole thing gets very complicated very quickly. Admittedly, Windows does a rather poor job of detailing what is going on.
still though, I do get those "windows must increase the size of your virtual memory" messages when the memory use is very moderate. why would that be?
That I'm less sure about.
Some programs (I know some versions of Photoshop have been known to do this) may try to allocate a large amount of memory at startup, or at other times -- but not for very long. There are also some other things applications can do (such as memory-mapped I/O) that can eat up virtual memory space but don't 'really' take up physical RAM. If you have no swapfile, or a very small swapfile, Windows might 'run out' of memory space, even though the application isn't truly going to use all the space it is asking for.