How mch difference will a sound card make?

[bsweet0us]

I am trying to finish up getting parts for my first cab and am waffling on the importance of a sound card vs onboard sound.

Currently I'm running XP SP2 on a 3-gig Intel Pentium 4 processor Abit motherboard
512 Mb RAM
200-gig primary HDD with an additional 80-gig HDD
Nvidia GeForce FX5200

I purchased the Altec Lansing VS4121 speakers with sub (2.1 channel) and would like opinions on sound cards vs onboard sound (currently Realtek AC97).

Don't want to spend much if I go sound card route, but I don't know what cards support 2.1 sound.  Thinking  Soundblaster Live! from eBay, but is it worth it?

I respect everyone's opinion, so please chime in!

Oh yeah, I've got MAME .111 and plan to play old and new games.  Also have Daphne and ZSNES and FCEUltra.

Don't steer me wrong!

[Xam]

I know my soundblaster live sounds much better than my onboard sound. I don't think you need much in the way of sound card. Most older arcade games didn't have very sophisticated sound...some of the newer ones do.

My MAME machine with have a basic sound blaster live and it has more than adequate sound quality.

Xam

[ahofle]

I dont' think it makes much difference performance-wise in MAME.  When I first setup my MAME cab computer, I was using the onboard sound and was noticing sound problems in some games.  I got a Soundblaster of some sort thinking it would help, but it didn't.  FPS was pretty much the same and the sound still stuttered.  Turned out the particular game was just too much for my computer.