Pagefile size reduced, But how & why?

The pagefile size will change on the fly depend what's running and how much memory/cache etc is needed. My Pagefile ia at this moment 12+GB and will down while start the computer to 2GB!

 

I've always changed Windows' default configuration of automatically setting it's own pagefile size to a set amount. Under XP I think I did 4x the recommended amount for the minimum size, under Windows 7, 2x the recommended amount and now under Windows 8 I find the recommended amount satisfactory, and then double those minimum amounts for the maximum size.

Keeping the pagefile from resizing reduces the file fragmentation of the pagefile and slight lag when Windows determines to increase the pagefile while you're doing intensive operations, whether working on large files, playing large games, et cetera. I don't know why Microsoft insists on having the pagefile change size on the fly by default.