Through playing BF3 I'd have lost sound all together or intermittently,spawn with no guns and generally laggy/stutter feel to the game.
No idea what caused this and a game reinstall didn't help, through looking on the battle log forums I came across a post which led me to this piece of software.
http://www.razerzone.com/gamebooster
Works with steam & BF3.
Since I used it with BF3 the above issues went now while I'm not sure if this was because this was of the above software but it certainly gave me an over all smoothness of the game.
and it's FREE
Nvidia have something like this but it doesn't remove application from memory and tweak registry setting like this tool but optimise the game setting for your GFX card. Its in BETA and worth a look if you are not comfortable with fiddling with the GFX settings yourself. Get it HERE (http://www.geforce.co.uk/drivers/geforce-experience/download).
Might make everything even more smooth for you DD.
DZ
Pretty cool DD