Dell XPS 15

Hi,

i have problems with my new Dell XPS 15:

6th Generation Intel Core i5-6300HQ Quad Core

8GB (1x8G) 2133MHz DDR4 Memory

1TB 5400RPM Hard Drive + 32GB Solid State Drive

NVIDIA GeForce GTX 960M with 2GB GDDR5

From the first start i notice some slowing in general (high memory use without working, boot times too long ) 

The slowing increse when i connect a monitor through HDMI port.

A clear sign of this, is visible by right-clicking on desktop. Without HDMI, the flag opens instantly, with HDMI connected, the system show the loading icon for 1 second and after opens the flag.

The monitor i use is a Philips 244E1 - Model n° MW1244T

I try to upgrade the drivers of graphics card with last relesed, but nothing is change.

I don't know what i have to do, it's not normal that a machine with this kind of setup have this kind of slowing,can you help me?
It can be a fabrication problem?

Thank you

Regards