The minimum size SD card you can use for Rasbian is 2GB, but it is recommended to get a 4GB SD card or above.

Card Speed

A Class 4 card, which is the minimum recommended has an average read/write speed of 4 MB/sec.  If you spend a little extra and buy a Class 10 card, you should find that the boot time is approximately 25% of the Class 4, as it should read at 10MB/sec.

However real world experience has found that that class 4 cards designed for random access perform faster than "faster" class 10 cards which are designed for block reading and writing.  See this post by the foundation as to why they have selected a Samsung class 4 card for the NOOBS distribution.

File IO Speed

See here.

Compatible SD Card Resources

We benefit hugely from resources on the web so we decided we should try and give back some of our knowledge and resources to the community by opening up many of our company’s internal notes and libraries through mini sites like this. We hope you find the site helpful.
Please feel free to comment if you can add help to this page or point out issues and solutions you have found, but please note that we do not provide support on this site. If you need help with a problem please use one of the many online forums.