xfce, gnome and kde

[Rafnews]

Hi,

i installed on a very old laptop Fedora 19. Firstly i must say that 
fedora is my favorite OS especially for very old hardware as it works 
everywhere.
so this laptop is for my son to watch cartoons and other children things.

when it runs KDE, cartoons are choppy...
when it runs XFCE, cartoons runs like hell...so fast, so well
when it installed Gnome (to test gnome 2 for example), well... it 
doesn't allow me to use the gnome shell at all... system display white 
screen and i must to log off and to chose another desktop

so how can i do to make KDE or gnome running movies like hell, like 
under XFCE desktop ?
thx.

A.