Originally Posted by kevinp
I found that the speed is what matters most. I ran CM7 on a 8 GB Kingston 4x card with virtually no problems. When I tried using a 10x card, I couldn't even get it to boot.
What matters for this use of SD card (i.e., running OS & Apps) is random read/write speeds for which Classes 4 & 2 outperform the higher Classes 6 & 10 which are optimized for sequential read/write speeds.
contains benchmark results for a wide number of SD card brands and classes.