How can I know the speed of an SD card before buying it?

[FAHMI BASSEM]

Thank you...

 

[bozza72]

goggle it, someone will have written a review or speed tested it

 

[alakazan]

sd cards have classes usually you can find class 4,6 and 10 . class 10 card are good for gamin and fast file transfer

 

[FAHMI BASSEM]

where can I find these details? because I went to a shop today and I couldn't find anything.

 

[Guytronic]

Check here:
https://www.sdcard.org/consumers/speed/speed_class/

Shop cards based on the SD standards.
Can't say much about brands.
I've never had a Samsung microSD fail or mis-write.

 

[ShinraCorp]

Here you go:

Class 2 2 MB/s SD video recording
Class 4 4 MB/s High-definition video (HD) recording including Full HD (from 720p to 1080p/1080i)
Class 6 6 MB/s
Class 10 10 MB/s Full HD (1080p) video recording and consecutive recording of HD stills (high-speed data bus)
UHS Speed Class 1 (U1) 10 MB/s Real-time broadcasts and large HD video files (UHS bus)
UHS Speed Class 3 (U3) 30 MB/s 4K video files (UHS bus)