Frankly, I would like to see any "Scientifix" (i.e. hard numbers) proofs of increased performance, for anyone using swaps on both microSd and eMMC. for every person trying it, including myself, on wide range of cards, using swap on microSD only was and is more profitable. Which is quite easy to explain, due to flash chip characteristic (mentioned I/O "conflicts").

/Estel

I see what you are saying. Since I am only interested in a clearly noticeable performance increase, I suppose the only proper way to find out is to try the dual-vs-single swap on my specific SD card. I could get a performance reduction or the noticeable improvement I want. Should be easy to notice with those criteria. If dual swap doesn't help, I agree that RAID probably won't give anything either.

Thanks for your input!

http://cs.joensuu.fi/~mmeri/usbraid/
You can modify the eMMC by booting Maemo (or Android/plain Linux) off of an SD card.
Backupmenu might work too (has a console), but I don't think it has the tools required to repartition the eMMC.
I don't know whether or not the standard power kernel has raid enabled, but you can just compile your own kernel to be sure.

Just try it. All this discussion about swap and whatnot won't result in any useable numbers.
Possible? Probably. Worth the trouble? No.