Jon Simpson
Addressing The Outmoded Swapping And Paging Strategy in OS X
… the swapfiles are allocated, grown and freed dynamically, too; so the first time you need swap space, it allocates 64M (yes, MEGABYTES) of swap; then the next file is ALSO 64 megabytes, and then the next ones double to 128M, 256M, etc… and when you stop needing that disk space it immediately expends heat and valuable processor time - scarce resources on a netbook-class machine - trying to give you that 256 megabyte file, back.
I’ve been generally more satisfied with the performance of the Rev C. Macbook Air than the original Rev A. I had, but because of the weak IO on this machine the paging really tends to make things suck - XCode and a long-lived Safari session is enough to trigger this behaviour. Hopefully Apple will look at changing the paging strategy either in a 10.6 revision or for 10.7.