Mouse pointer lags

Hi,

I have a brandnew MacBook Pro (Retina, 13-inch, Early 2015), 3,1 GHz Intel Core i7, 16 GB 1867 MHz DDR3, Intel Iris Graphics 6100 1536 MB with an annoying problem: The mouse pointer lags as you can in this little screen recording: http://design.rubenz.at/apple/freezing_mouse.mov.

It occurs when using the trackpad but also with an external USB mouse.

What I have tried so far:

• updating the OS from Yosemite to El Capitain
• Installing El Capitain from scratch
• Checking the system's resources with htop: there is nothing special going on.

I am really clueless, because the behavior is so weird. Is there anyone who could help me on this?

Johannes