32GB Sandisk Ultra MicroSD card slow and overheating!


I recently bought a 32GB Sandisk Ultra MicroSD  from Amazon and I’ve found it to by slower than advertised. Even though Class 10 cards should achieve a MINIMUM of 10MBps transfer speeds, while transfering big files, I’m only getting ~8-9MBps tranfer speeds.

Also, I’ve noticed that when the card is plugged into a device, it get’s hot to the touch. When I’m transfering data the card gets even hotter!

As of this time, the card is fully functional, but I’m contemplating of returning it as it seems to be at the point of being really close to failure. Is it normal form Sandisk Ultra MicroSD cards to behave this way, or should I return it?

  1. Warm is OK, hot is NOT.
  2. A 1-2mbps difference really isn’t enough to worry about, but it depends on what device it’s in and/or the computer/USB capability doing the transfer.
  3. What type of device is it in? Class 10 cards are not designed for nor work well with some devices.