I was recently asked by a *buntu user why the games he'd like to play "stutter". I've asked him which graphic card he has, but he had no idea, nor did he know where to look.
There are several ways to get this information, including the canonical 'lspci' and 'lshw' as well as 'hwinfo'. By far the easiest, however, is inxi. Graphic card and driver are obtained by 'inxi -G', but even the full information delivered by 'inxi -F' is delivered in a way which is pleasing to eye and mind:
On Arch, inxi is in the community repository. On Debian Wheezy, you can get inxi as described here.