Probably not possible with only one drive.
It would some work to find out, but I think that some primary directories are under constant access (like the root /usr /etc), and the swap partition may never be allowed to spin down. This is only good if you have the user space on another drive or if the system resided in a ram drive. I think some experiments were done some years back, but I do not know what the results were, but I think it was not good. Most of the system directories need to be on the root drive to even get through boot.