Why does my micro sd run so slowly in my phone?

[AC Question]

I recently bought a class 10 128gb micro sd for my LG G4 and lately it has been so slow. I cant even set my camera to store photos on the sd card because it takes about 10mins to save one photo or it doesnt save at all and just as long if I try to delete something from the sd card. When I bought it, it worked brilliantly and was super fast but now it is slow. If I connect my phone to my laptop and try to access and copy files to the external memory(sd card) it cant complete the transfer and says the device is not responding, but if I remove the sd card and put it in an sd card reader and then in my laptop I can copy files to it lightning fast. Why would this happen? Previously I had a 64gb micro sd card and never experienced any of these problems.

 

[420lyfe]

Could be due to multiple reasons.
1. Support
2. SD card reader damaged
3. Generic SD card.

Not sure if anything else could be responsible.

 

[anon(632115)]

Class 10 on a card that size will be slow

 

[B. Diddy]

Welcome to Android Central! The SD card could be corrupt, defective, or counterfeit. Install SD Insight to see if the card is genuine or counterfeit. Counterfeit cards are programmed to report more storage than they actually have, and if you try saving more than the card can actually hold, then files can start getting corrupt.


If it's a valid card, then go to Settings>Storage, Unmount the card, remove it, and insert it into your computer. Can the computer read these files? Backup as much as you can right now, then run chkdsk to look for bad sectors: http://forums.androidcentral.com/am...guide-using-chkdsk-fix-corrupted-sd-card.html.