if you're buying a PCI-E sound card (like the Creative Sound Blaster Titanium), make sure you have a free slot for it. a lot of the high end motherboards have 3 PCI-E slots, but the newer graphics cards are pretty think so if you have a crossfire / SLI, one of your slots might become inaccessible.
I am an owner of the Asus Maximus 2 Formula. Which like the Asus Crosshair 3 Formula, sports the same riser soundcard called "SupremeFX-Fi" (meaning it's not a fully fledged soundcard and cannot be used just on any other mainboards). And i have done some research on the the quality of this device recently to see how it goes up against a dedicated soundcards such as: Creative X-Fi, Asus Xonar, Auzentech. As i was planning to upgrade my audio component to a higher standards.
The sound chip behind it is NOT a creative X-Fi audio processor at all. It's rather an Analog Device AD2000B. The X-Fi in the SupremeFX-Fi they mention is rather the X-Fi software that's included that enables certain "X-Fi features" such as: CMSS, Crystalizer and as well support for EAX 1,2,3 and 4. Exactly as what Creative have done with X-Fi Extreme Audio product, which is also not equipped with the X-Fi APU but using X-Fi software to brand it "X-Fi". Since it's not a real X-Fi audio processor, you can understand there is no hardware acceleration for games. The SupremeFX-Fi software included only let you uses "Entertainment mode". Where the real X-Fi boards has access to other modes, such like Gamer mode.
When it comes to 'reviewing' soundcards, lots of websites only does listening test, but there is this software called Rightmark, which is used to test the soundcard signal quality. I did found a website which did a Rightmark test with the AD2000B audio chipset: http://www.bit-tech.net/hardware/motherboards/2008/05/2...
You can use these numbers to compare them to dedicated soundcards reviews where they also have used Rightmark.
The AD2000B is capable 5.1/7.1 output with 16/24 bits bit-rate with sampling-rates of 44.1/48/96/192 khz, this is same offering as the dedicated sound-cards (Xonar, X-Fi's). The audio quality isn't too shabby for an onboard audio solution; It's one of the better ones you will find (the other better one being ALC889a). But the AD2000B can't encode DTS or Dolby Digital Live bitstreams. If you require those feature you might wanna look into the Asus Xonar series, which offers great audio features for the PC (without the software headache as many Creative soundcards suffers from).
So what basically comes down to. If you are a gamer (and i assume you are since you thinking about to get yourself a Formula serie product ) and you want to upgrade your audio. Look into Asus Xonar D2X or Auzentech Forte. The downside is they aren't exactly cheap, they cost about the same as a decent graphics card. Except a good soundcard last a whole lot longer than a video card.
But if you're not willing to pay a lot for a soundcard, i guess you could consider the cheaper Asus Xonar DX or Creative X-Fi Titanium.
Tho consider my own recent experience with X-Fi software, i can't recommend the Creative solution to anyone.
But don't just blindly believe in what i told you tho. Do some research on your own on Asus Xonar DX, Xonar D2X and Auzentech Forte (X-Fi based product).
Ehe, I've used creative cards for years, no problems. Asus mobo's and creative sound cards. My current mobo came with that asus sound card and I just chucked it cause I figured it couldn't be much better than on board sound. Nexu's post was pretty interesting.....strictly because someone put so much research into proprietary sound. Anyways, only problem I've EVER had with creative sound cards is that with my current one and vista, I had to use that "alchemy" software to get the full 7.1 in old software. IE, counterstrike....other than that, their performance is pretty strong, and I've never had one cook. The one I've had since 2003, and this one, XFI, I've had for about 2 years.