After upgrading from Ubuntu 14.04 to 16.04 on a Dell E6330 laptop with core I7 cpu, when running in the default Unity desktop with external USB keyboard and mouse, if I don't touch the keyboard or mouse for roughly 5 seconds the mouse apparently snoozes and it takes about 0.5 seconds of mouse motion before it resumes functioning. Brief bumps of the mouse are usually ignored and the motion is lost. The keyboard doesn't lose keystrokes and pressing a key before using the mouse prevents the mouse hesitation.
In my preferred XFCE desktop the issue is far worse. Keyboard input is also lost. Sometimes it can take several keystrokes to 'wake' the system. In some apps such as PyCharm the problem seems worse and the system is more resistant to "waking" than in other apps such as gedit.
The laptop's internal keyboard and pointer stick work fine. I'm not 100% sure about the trackpad as it can lose very slight motions after a pause but I think it might be its normal behavior.
On further testing I just discovered that if I plug my mouse into a USB port on the laptop instead of through my hub the problem goes away.
My question is does this sound like a power saving configuration issue and if so what settings or tools should I use to resolve it?