How new of a board are we talking here?...SB sounds great, and on-board sounds are terrible, on my 7 year old Giga board

It honestly comes down to you. As others have already mentioned, onboard has definitely come a long way, but it's still by no means the same as having a dedicated sound card. However, many people are 100% happy with their modern (and even old school) onboard sound and that's awesome, I'm jealous actually; it would save me a lot of money!

Personally I have not met anyone that I have convinced to install a sound card to not notice a difference right away in the quality of audio. Although of course you need a quality pair of speakers/headphones, if you just have some run of the mill desktop speakers there's only so much they can do.

As far as game performance increase, I would say with most modern games, and with the power of modern multicore processors; it's going to be negligible as with games such as BFBC2 or BF3 the sound is actually processed on one of the cpu cores, even if you have a dedicated card, and then it's fed through the card.

Before I got my ProFire I had an Audigy 2 which out did all of my onboard audio processors from when I bought it back in 2002 until about 2010. My brother also runs an X-fi gamer, although I would have to say you may want to avoid Creative because of their drivers, they are by far the worst I've ever seen and it doesn't seem like they have ever really improved. Although I've heard nothing but good things about Asus and their Xonar line.

And remember, if audio is really important to you don't let anyone tell you spending a lot on quality equipment is a 'waste of money'. Nothing is a waste of money if you get enjoyment/use out of it. Nothing is more important to me than audio, and to me even these BX8a's don't cut it, once I get some money I'll be getting a nice set of Focals :)

Good luck!

Edit: Just an update, in my comparison between my Audigy 2 and onboard audio processors, I was not using any special audio effects or 'enhancements', especially not 'crystalizer' or the 3D speaker effect, just a pure audio comparison.

Now I understand that without a good set of speakers/headphones you won't really hear a difference, but what level of quality equipment are we talking for the headphones? What quantifies a "good" set?

I personally have a set of JVC HA-RX700's, bought them based on their reviews.
Would this level of quality (good or bad, Im not really an audiophile) lend itslef to a separate sound card?

Is there something that can be used as a standard?

That's a very difficulty thing to quantify, but I would say that you would tell the difference between onboard and dedicated with those headphones. Headphones are much easier to make 'sound good' since the drivers are located right outside your ear and so they don't suffer from audio cancellation/reflections/etc.

http://www.hometracked.com/2008/01/2...monitor-tests/

This website has some useful audio tests you can use and you may be surprised by what frequencies seem to disappear when going through the sweep.

I would say anything $40 or over is probably going to be a decent enough set of headphones (or possibly speakers). However, on what can be used as a 'standard' I think you'll get as many different (and probably equally valid) responses since there are just a staggering number of brands/types, many overlooked, and some over hyped. Personally, I say you can't go wrong with a pair of Grado SR 60i, they go for about $80, or Sennheiser HD 280's (newegg has em on sale for $99) or pretty much anything Denon or Sennheiser (that's $40 or more).

I considered all of those actually, the Grado and Sennheiser's especially.

Grado makes some incredible headphones, I've always wanted the RS1i model, maybe someday :)