Having several memory cards types available is simply too much. In our opinion on the long run only four standards will be alive: CF, MS PRO, SD and xD. MultiMediaCard (MMC) and SmartMedia (SM) are pretty dead right now, specially because of their very low transfer rate. In fact, xD was created to replace SmartMedia (SM) and SecureDigital (SD) was created to replace MultiMediaCard (MMC). MS has a low transfer rate compared to newer standards, but Sony pushes this standard really hard, so we will be seeing Memory Stick alive for some years, util it is completely replaced by MemoryStick PRO, which provides a really good transfer speed.

We created a graph (see below) comparing the speeds of the several cards available on the market today. You have to keep in mind that these rates are maximum and you may not achieve them with your camera. Also, these speeds are "transfer rates", which means "read speed". Speed for writing data in the card will be always lower than the numbers shown. The numbers are given in KB/s.

We didn't create a graph for write speed because we couldn't find what is the write speed for some cards like CF and SD. As soon as we have this information we will update this tutorial and create this chart.