CS6 stitching is in Ps. In CC the stitching is in ACR. When the swapping started it was slower than without swapping, but only a little slower. I think the only delay was for part of the data that already been worked on to swap out. Remember, my test is based on a 16 shot D800 data set. There are stability issues running 4 sticks of memory. Right now 16x2 32 GB memory kits are pricey. Memory keeps getting cheaper and faster. Who knows what I will be able to snag in a year. It's fine to have 32 gb of memory but for the occasional large pano it doesn't make sense for me. Forget about 8 gb, that's for gaming and MS office.
I am not saying 16 gb is enough for everyone or even most photographers, but it is enough for the way I work now, and probably for while.
If you have a desktop with 4 sticks of 8 gb you can try some tests. On a notebook, it might not work the same as there are only 2 sticks and going to single channel is a hit.
Let me mention this, Intel makes a tiny barebones computer, the Nuc. I have one of the lower powered models in use as a dedicated home theater PC. Their latest offerings have I-5 and I-7 notebook Skylake chips. Add memory, SSD, operating system and peripherals and you have a computer. They go together with fewer hitches than an ATX/mATX system.