Writing, reading, ect copy very fast but it's on I is not actually tested flow rates with suitable software.
But to use an average person like me, great speed is very good !!
Personally, I use it with a camera Nikon Coolpix S6300 and it is perfectly fine for both the photos videos !! The card is recognized and works perfectly with.
Moreover software downloaded is available which is used to recover lost data .. hoping it never used !! ^^