What difference does SD card type and size make?

General programming chat and advice for beginners

3 posts
by shakeyfinch » Sat Jul 07, 2012 3:07 pm

I have got my Raspberry Pi up and running using a Sandisk Class 2 2GB SD card I had lying around using the excellent instructions here http://elinux.org/RPi_Easy_SD_Card_Setup.
In the list of Working SD cards here http://elinux.org/RPi_VerifiedPeripherals some people are using upto 32GB, Class 10 SD cards.

Could someone explain...
What does the SD card do?
What is the advantage of one SD card Class/Size over another for the Pi?
Does it work like the C:drive on your computer? can you store stuff on it?

I am a complete novice.
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by itimpi » Sat Jul 07, 2012 3:49 pm
Yes - think of the SD card as the equivalent of the hard disk in a Windows PC.

Size is simply the amount you can store on the card. Like with a hard drive one has to balance cost against having more free space. What size makes sense really depends on how you are going to use the system. It seems a practical minimum is 4GB although many prefer more.

The class is a theoretical indication of the speed, with higher class being better. However the class is normally an indication of read speed rather than random write speed and both affect performance. Another point is that there have been some problems with class 10 cards although it looks as if the latest kernel updates may have largely resolved them.
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by chalky_stewart » Sat Jul 07, 2012 4:02 pm
Yes itimpi has got it correct with his analysis. :D
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