Increase DDR memory out of motherboard, i.e. USB?

"Upgrade your memory.

Install a card that takes ddr of some flavor, and plugs into a drive port, and use it for swap (that is as close as you are going to get to more memory).

Use an external drive for swap.

Use an exported network file system for swap, or a raw device (iscsi or nbd).

If you cannot increase the memory, all you can do is add swap, and make that as fast as possible."