Server rentals :: NFOservers.com

ok. i have tried a few different programs and the one i like the most is teamviewer. i want to know why sometimes i could get such serious lagg with any of the following remote desktop programs, i mean like sometimes the screen wont change for up to 5-10seconds, and its not my internet connection.

gentlemen, i need to know how important is my upload speed when trying to manage my rented server with vnc, and why does my vps lagg when i logg in to use it with remote desktop, unlike when i control it with teamvier or vnc?