sexy experience with a graphic card

More graphics RAM and motherboard RAM the better. But you must be running a 64 bit operating system to use it and preferably running software designed to run in 64 bit mode. The more graphics RAM you have the more it takes work from your CPU so releasing more power for it to do other things. You really need to be a serious gamer or into video editing and manipulation to warrent spending $1000 on the top graphic cards - and we are talking two cards coupled on the mobo! Resolution is governed by the native resolution of your screen, if you have a flat screen. With an old CRT monitor you can crank up the resolution. Maybe have more than one monitor?

Yes and no. You will get a better resolution with certain cards yes but that also comes down to your monitor/s. As for performance, obviously between cards there will be a performance difference whether it be slight or huge (usually reflected upon by the price). As for the 8GB ram along side a card, it will make very little difference how much Ram you have.

Lol..in graphic card's performance,it's core clock,memory clock,shader clock,pixel fillrate,texture fillrate,memory bandwidth etc factors matter,not how much memory you have got as far as you don't have huge screens.