So do you need a low capacity, plain old SD card, a mid-sized SDHC or a SDXC? Most cameras and smartphones today use high megapixel counts and large files — a 2GB SD card would fill up pretty fast.

Back when the GPX was made, the maximum capacity of an SD card was 2Gb, a figure that must have seemed huge when the standard was created, but by the middle of the last decade was starting to look ...