i have lumia 640xl and i am using 32gb class 4 sd card. but it is working very slow.

[Ayush JAIN]

The files take too much time to open and some files fo not open..
Which class sd card will be best for Lumia 640 xl..???

 

[emjey]

I use 64GB class 4 too Samsung. Its extremely fast in mine. Format ur memory card once