Displaying pictures jogs disk

This may be somewhat off topic. Anyway. I'm using a laptop computer as my X terminal, while I run XEmacs (21.2) on a different machine. I have set the disk on the laptop to go to "standby" mode when there is no disk activity. (I think computers should be seen and not heard.) The only two things that make the disk do something is when I read text that requires new fonts to be loaded (which the X server on the laptop is responsible for), and when I view pictures in XEmacs (for instance, picons). I guess this is because the X server is doing something or other, but why does XEmacs displaying pictures require the X server to fiddle with the disk? -- (domestic pets only, the antidote for overdose, milk.) larsi(a)ifi.uio.no * Lars Magne Ingebrigtsen