XPS 13 (9343) - Video preview stuttering when editing

Hello, 

I started trying to do some video editing on my XPS 13 (9343), equipped with I7-5500U@2.40Ghz, Intel HD 5500 integrated graphic, 8 GB RAM. I always run it on AC, not on battery.

The problem I'm experiencing is: with every video editing software I use (tried Pinnacle Studio, Adobe Premiere, Openshot Video Editor), the video preview will render 2-3 FPS at most. CPU skyrockets at 100% and the video keeps freezing, like in constant buffering. I'm trying to edit FHD videos (1080p60).

I tried lowering preview resolution and quality, with no success. The performance is the same, whether I preview at 1080p@60FPS or 512x288@30FPS.

Verified on Dell Update v.3.1.1, and already applied all available updates, including BIOS ones. 

Are my PC specs too low, or have I got a problem? 

Thanks.

Mattia