Adding external ram to 2014 MacBook Pro
The internal RAM is soldered to the motherboard (i.e. totally user-untouchable), but for external RAM, you're welcome to check out this article at your own risk.

UPDATE: After having done some research, apparently RAM disks are exactly the opposite of what I'd thought. They actually turn a segment of your RAM into hard drive space. It still promises massive speed boosts, though, so you should give it a try if you're up for it!