simple, I have a few old DDR2 RAM chips laying around, and would like to use the Ram chips for a pager file on my PI. is this possible?
You can get a ram disk (not a disk in the ram, a ram as a disk) and convert its SATA output to USB. But you will be limited to the USB speed and maybe you will need to feed it with additional power (maybe with a USB hub that has external power supply).
Thus, It is possible but I think it is not practical or efficient.