Hm, In fact, I'm all for about MOAR SPEED myself Yes, I mean older tests done via pendrives through USB. Maybe it's indeed outdated, and I discarded idea too hastily? If yes, sorry for that, and lets look at it closer. The two (related) things, that make me think it won't work well:

1. On N900, using 2 swaps at the same time - one on eMMC and one on microSD, with equal priority - doesn't seem to help with speed, at all. In fact, it even gives *worse* results than swap on microSD *only*, due to I/O conflicts between /home and swap on eMMC (see point 2).

2. We have hardware controller on eMMC, that (transparently for OS - no control for it, at all) does some "nice" things, like forced hardware leveling. Now, it's well know, that flash memory doesn't have problems with multiple reads, but simultaneous multiple write attempts cuts performance by orders of magnitude (so-called I/O conflicts - not real "conflicts" in true terms, just I/O's getting in the way of each other, and slowing things down)

*if* you would be using software RAID on eMMC and microSD, you would have simultaneous I/O on both eMMC and microSD all the time, coupled with I/O for swap. IMO, it will lead to same performance penalties as in point 1. during normal usage, it can be avoided by having swap on microSD *only* (so I/O from opt, home, etc, doesn't get in a way with swap, and other way around, as they're two separate physical devices), but if you RAID them, there is no way around it.

/Estel