In my view, if you need to use the desktop, Windows is quite efficient when it comes to RAM/CPU usage. I always viewed Linux desktops as more of a resource hog. However, if you want to use the device as a server of some kind (DNS, http, mail, ftp, routing, NATting, CIFS [that's windows file server], NFS, etc), then Linux will shine there because you don't need to even load the Linux GUIs to run those. Those are perfectly configurable with command line tools and a simple text editor. Your memory can be in the low double digit figures to be able to run a fast and responsive server on a lan with Linux (or FreeBSD, OpenBSD, etc).