i downloaded planet side 2 on my new pc and it took 2 and a half hours to download so i thought i would try download the game on my 5 year old laptop off the website planetside 2 and it took 5 minutes
The file PS2_setup.exe from the planetside site is only 19.2MB. Run that, and then it will go get the rest of the game.
From Steam, it is probably the whole game.
^ Exactly that. What you downloaded from Planetside was nothing more than a downloader that will get the game for you. Steam on the other hand is downloading the entire game.