well you're probably reading some old reviews (being as its the GeForce 8 series), so back then, yeah it probably could play most games on max... but now, with games like Crysis or STALKER:CS you'll need SLI to get them running well at max settings.
Sapper is right... CPU OCing is great for increasing performance (not so much in games tho) because you can do OCs of up to about 50% without any elaborate cooling setups, but with GPUs, you'll only really get maybe 25% extra on the clocks without some sick cooling... even tho you only get a bit of an OC on your GPU, this could be all you need to get. say, an extra 5fps on your games, which could be the difference between being playable and not