Micro SD cards - class 4 or 6 or 10 ?
Micro SD cards - class 4 or 6 or 10 ?
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Discussion

oblio

Original Poster:

5,571 posts

251 months

Friday 6th February 2015
quotequote all
Hi

Could someone explain to me in laymans terms what the difference is between the classes on Micro SD cards?

I have just bought a dash camera which says it can take Class 10 but a resected reviewer of such things suggests a Class 4 or 6 instead

ta smile

dogbucket

1,254 posts

225 months

Friday 6th February 2015
quotequote all
Transfer speed the card can support (2MB/s, 4MB/s, 6Mb/s, >10MB/s. Chances are the bitrate of the video from a dashcam does not actually need a class 10, but they are cheap enough so getting a 10 doesn't matter.

oblio

Original Poster:

5,571 posts

251 months

Friday 6th February 2015
quotequote all
Cheers thumbup

So if I got a 6 as recommended I wont be disadvantaged?

cheers smile

FurtiveFreddy

8,577 posts

261 months

Friday 6th February 2015
quotequote all
The class quoted on the card is the MINIMUM write speed. It may be higher than that, but you wouldn't know until you got it and tested it.

It is possible a reviewer has tried a class 6 card in a device which is designed to use a class 10 card and found it to work. That doesn't mean you will necessarily have the same experience.

A while ago, I bought a batch of class 4 SD cards and they quite happily worked in the HD video recorders I was using. So when I ran out, I bought some more. Exactly the same manufacturer and C4, just like the first batch except these newer ones didn't work.

When I tested one of the older cards cards against the new ones, I found that the old C4 cards were actually working above C6 spec. whereas the new C4 cards were only just above C4 spec.
I confirmed with the manufacturer that both batches of cards were genuine and from their factories but they couldn't (or wouldn't) tell me why I found such a big difference between two batches.

It may have been they couldn't get the right components for C4 cards when they had orders for them, so just re-labelled C6 cards instead. They would still be making a good markup.

So what I'm saying is that you can't be 100% sure a C4/6 card will work in a particular recorder unless you test the specific recorder/card combination yourself.

Shaoxter

4,519 posts

148 months

Friday 6th February 2015
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In theory, UHS > class 10 > class 6 > class 4 because as previously mentioned, that's the minimum write speed in MB/s.

Brand is also important though, some devices are notoriously fickle for which brands of SD card they accept so check your manual. To be honest any class of card will probably be fine for a dash cam unless you're recording in 1080p+ 60fps or something (which would be unnecessary for a dash cam).