Why would ExpressCache.exe appear to be constantly using an external HDD?

Question

I bought ASUS VivoBook S550CM with hybrid drive SSD/HDD. There are many pre-installed Asus utilities, ExpressCache included.

Here is the problem: every time I connect any external USB HDD, the LED indicator on external HDD starts to blink. When I open Resource Monitor I see that ExpressCache.exe is constantly writing/reading something from external drive. See screenshot. So all external drives are being constantly accessed. This is slowing them down when I want to use them and they are very noisy. I tried to reinstall the Asus ExpressCache utility and nothing changed... Hard reset didn't work too...

Any idea on how to fix this...???

Screenshot:

Answer 1

A possible reason for the activity is that there is a feature within ExpressCache that will defragment the disks connected to the system. This is typically done as a background task and will not effect the performance of the system although you may see the activity a bit high at the beginning but as the disk drives become defragmented the activity will be reduced to almost zero.