Referring to the SDHC cards (SD cards over 2GB) they are rated with 2, 4, and 6 classes, these represent the minimum write speed (in MB) if the card is empty, read speeds are normally higher than write. I have 2 8GB cards one is class 6 and the other is class 2 and I notice a difference when canola is scanning them. The class 2 card is really slow compared to the class 6.

In my N800 I don't run any swap. I did for a while but everything runs fine without one for me. I run the stock (low speed) kernel.

Now in my 770 it uses a swap but I have flashed the high speed kernel and notice a huge difference with the operation speed.

Both boot from internal flash.