An 8GB micro SD card is more than enough to install Linux distributions Raspbian, Armbian, Ubuntu on Raspberry Pi, Pi Zero, Orange Pi, Banana Pi mini-PC … The most important point is to choose a fast SD card . The minimum to obtain a reactive system is to opt for a class 10 (10MB/s). It is best to buy two SD cards and make a regular backup to be able to restore the system in case of problems.
Class 10 SD cards are optimized for write and fast read operations. There are other equivalent designations: microSDHC, microSDXC, SDXC II or SDXC UHS-I. Initially developed for camcorders and digital cameras, they bring a real performance and security gain for Raspbian. We also find these cards under the reference V90 up to 90MB / s at a very reasonable price.
Which micro SD card to use for the Raspberry Pi?
The sdcard.org site has posted a summary table to help us choose the card according to the desired sequential write speed. It was developed for digital cameras or video recorders but it is fully usable for use on a mini-PC Raspberry Pi, Orange Pi, Banana Pi …
The following table shows the table on the sdcarg.org site, taking into account the needs for use on a mini-PC. It is best to stay in the green zone for good performance.
|Minimum write speed (MB/s)||Classe (1)||UHS (2)|
U3 or U1
|For video recording (3)|
from V6 to V90
(1) The old classes simply indicate the writing speed. A class 10 card should therefore achieve 10 MB/s.
(2) Then, with the increase in the quality of video recordings, classes U1 and U3 were created. The U1 class corresponds to a speed of 10MB/s. The U3 at 30MB/s.
(3) Probably to take into account the old 6MB/s card (?). The names V6, V10, V30, V60 and V90 were created. The figure following the V corresponds to the minimum theoretical speed in MB / s that the card can support.
Manufacturers add their names to complicate the matter:
- microSDXC or SDXC
- SDXC UHS-I
SD cards were not designed for such heavy use (unlike SSD flash drives). It is therefore preferable to buy a second SD card and clone the main SD card regularly (after each update, every month). In case of failure, you can restart your server in a few minutes without having to reinstall everything. Some home automation software (Jeedom in particular) requires to re-include the peripherals after a restoration. It is therefore much simpler to restart the Raspberry Pi with a system clone. Follow this tutorial to learn how to backup an SD card.