Integrated Graphic VS Dedicated GPU

Hello,

I'm wondering if there's any difference in using Integrated Graphic Card or Dedicated GPU for SL.

I've made an empirical test and results are similar, but maybe I'm missing something.

For the tests:
1) I've run SL on Dedicated Graphic Card
2) opened a sample file
3) run a preview of the full project while recording the screen
4) closed SL and restarted my laptop
5) switched to the Integrated Graphic Card
6) opened the same file again and recorded again while generating preview

You can see the results in the attachments ("Integrata" means Integrated Graphic Card, the one on the motherboard).

What is your experience about this topic? Is there any evidence to use a dedicated graphica card instead of the integrated one?
Thank you