User Guide

15
Classifying Memory Cards
There are three main types of SD card, with three physical-size
variations and several speed classes of each.
• Standard SD cards are available in capacities ranging
from 4 MB to 2 GB.
• Secure digital high capacity (SDHC) cards are
available in capacities up to 32 GB.
• Secure digital extended capacity (SDXC) cards are
available in capacities up to 2 TB.
Full-size cards are approximately 24 mm wide and 32 mm long.
miniSD cards are slightly smaller, only 20 mm wide and 21.5 mm
long; and microSD cards are slightly smaller again – 11 mm wide
and 15 mm long.
Raspberry Pi 2 Model B devices have a single microSD socket on
the underside of the board. You cannot use full-size SD cards
with this model, but microSD cards are often packaged with
adapters that allow the microSD card to be used in a PC’s card
reader.
Figure 5. Full-size and microSD cards
As memory cards are made by many different manufacturers
(over 400), deviations from the standard can occur and prevent
the Pi from working with a specific card. If you are intending to
buy a new memory card for use with your Raspberry Pi, you can
check the compatibility list at http://elinux.org/RPi_SD_cards to
ensure that you purchase one which is known to work.