You don't need to know the type of RAM. 7GB is good.
It all depends on your rig. In a sense desktops are superior to laptops, but if your desktop is a year old with standard specs and your laptop is brand new with the highest specs in the market right now then obviously the laptop would surpass your old desktop. Unless, of course, you upgrade your desktop.
No matter any limit, if both the desktop and laptop have the highest available specs in the market right now the desktop would still surpass the laptop because of limitations.