Inefficient Acer Liquid E2

I bought an Acer Liquid to recharge E2.
It does, but about 2 times slower than the USB cable provided by Acer (either USB to the PC or the Acer transformer).
Data transfer between the PC and the SD card is also a little slower (approx. 10%).
In short, a little disappointed, but Acer does not sell specific USB cables, I do not have better solutions to propose.