MicroSD cards have a limited life, and the more you read and write to them, the shorter their lifespan. In a BeagleBone Black this makes things a little tricky, the microSD card gets a much tougher workout than it normally would in something like a digital camera.

A photo of a SanDisk extreme microSD card installed in a BeagleBone Black.

Up until now, I have always just picked up a cheap microSD card to go with my BeagleBone Black. Unfortunately these microSD cards are often low quality and didn’t last very long, with some failing in as little as a month.

So now I only get ones that feature wear levelling. The cheap microSD cards don’t have any wear levelling, and the BeagleBone Black gets into situations where certain areas on the microSD card gets written to over and over again until it wears out and fails. The BeagleBone then comes along and again tries to the use the same worn-out area, and promptly chokes. All despite other areas of the microSD card being hardly (or not) used at all!

The more expensive cards with wear levelling won’t just keep pummelling the same spot on the disk over and over again. Instead, it will try and spread wear out over the whole disk. A little like rotating the tyres on a car, wear levelling ensures that each part of the disk decays at about the same rate.

An Illustration showing difference in microSD card deterioration with and without wear levelling

I also get microSD cards that have way more space than I need, at least 8GB. This further increases the longevity of the card by increasing the total ‘surface area’ that will eventually wear away. With wear levelling, more free space means a longer lasting microSD card.

Mico SD-Cards compatible with the BeagleBoard Black: