The best place in the case of performance for the swapfile is the ramdisk (RD) containing your private files/settings. Alternatively you can choose a Compact Flash card (CF) or a Secure Digital card (SD). Keep in mind, if your system uses the swapfile, the performance depends on the read/write access speed of the medium containing the swapfile.
The use of the swapfile is switched off during (re)boot.