A rooted Android mobile.
A Root Explorer like ES Explorer.
There is a way to speed up the SD card on your android. With this change the contents on SD card can be accessed faster. This includes accessing the Gallery, any app installed on SD card, File Explorer etc. Also there is a slight increase during file transfer to PC on the USB mode. Follow the steps below to accomplish this:
Open the Root explorer on your mobile.
Browse to this location: /sys/devices/virtual/bdi/179:0
Open the file read_ahead_kb and change the existing value (probably 128) to 1024 or 2048 or 3072 and save the file.. Try one of these values to see which suits your mobile. A value of 2048 is recommended. In any case upon saving the file there will be a marked increased in speed. Test it by opening the Gallery and see the difference.
Note: Upon rebooting the mobile the changes are lost.