[citation][nom]merikafyeah[/nom]The GTX 690 is the clear winner in my eyes, especially since there is a two-slot water-cooled version."Just Because You're Fastest Doesn't Make You The Best" pretty much says it all.The Radeons make huge concessions for the sake of performance:1. Bigger size. Three slots vs two. Quad Crossfire with two cards becomes virtually infeasible.2. HUGE power draw: Equals more heat, hence more cooling necessary, hence bigger size.Exceeding PCI-E specs is very worrisome.I think TWO GTX 690s would consume about the same or maybe even less power.3. LOUD. +Coil whine which is even more annoying than just loud.4. LOTS of microstuttering (virtually unplayable without using third-party software).5. Price. Let's be real. $1300 is optimistic, and availability is a shot in the dark.Pros:1. More FPS. Doesn't matter though unless you're using multiple displays, but that comes with the HUGE downside of giant bezels in your face.2. Little to no microstuttering with third-party software. The only saving grace but doesn't add a whole lot since GTX 690 microstuttering isn't that bad.Calling these three-slot monstrosities "inelegant" is possibly the nicest thing you could say.[/citation]
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&Order=BESTMATCH&Description=radeon+hd+7990
PowerColor has two 7990s, one is going for $1000 and another for $900. Where are you getting this $1300 number from? Sure, availability is poor, but the pricing is not.
Two GTX 690s consume a good deal more power than a single 7990. Yes, the 7990's power consumption is far too high, but lets leave exaggeration out of it.
Why is exceeding PCIe specs that worrisome? The cables are more than capable of handling it, it's fine.
Quad Crossfire is easy. Simply get a system with eight expansion slots such as the Gigabyte G1.Sniper 3 with a case that has eight expansion slots too (very common among higher end cases) and you'd have a full two slots for air flow between the top and bottom card, that's plenty. Heck, even one slot of airflow with a much cheaper board and case would probably be just fine. What I'd be more worried about is getting a PSU that can handle the load and the ridiculous power bill entailed.
Tom's only said that the Power Cooler model had bad coil whine, not the HIS model.