Quote Originally Posted by Peter View Post
What's the reason for that? Because i dont understand, my next question would be : is it the same for VGA? Now i connect graphics to splitter/booster and then to the projector.
Chances are you'll be fine but when you plug a string of video devices together, you run the risk of noise and feedback. Some noise is okay but even if you don't visual see it, there could be damage done to your video cards as they are more delicate than other components in the chain. The isolated splitter is a good idea to protect your gear the same way you would use a surge protector.

it's not necessary though.