Cheap soundblaster. I had been using onboard sound for about 18 months when I stuck a 24bit Sound Blaster card in my computer so I could try to get 5.1 sound which wasn't possible solely via my motherboard (even though it supposedly can). I couldn't get the 5.1 to work with this one either (why they design these things so stupidly is beyond me, I can't be the only one who wants to connect my computer to my 5.1 home theatre system) but ... games ran about a million times faster than before. I was having to use middling settings in HL2 and still got stuttering and slow down. As soon as the board was in, it told me to max out everything and it still ran much smoother than before, same goes for every other game I 've got.
Go for it.
cheers