Originally Posted by kswindell
Most of its use will be gaming. I tinker with photoshop an some video editing an stuff. I would also want to try an HTPC stuff with DVR an such. As well as stream my iTunes content either to other computers or to a larger tv i'll have on the wall in my office. I have a 32" samsung 1080p flatscreen that i would like to get 2 more of to have 3 monitors.
Part of what I'm trying to do is simply get it built beyond specs now so that it can last for several years. With the ultimate goal of being able to run the 3 monitors together at full specs on most any game.
I don't totally understand the over clocking an how one card can drag this down an such. At the end of the day I'm going to trust you guys to help me come to a final decision on everything.
You also said that the 6990 is loud an hot? How loud are we talking. i would like it to not make to much noise. and I'm going to build a rather over the top water cooling unit so i don't imagine heat will be an issue
When you run two or more cards in ATI's Crossfire, they run at the clock speed of the lowest clock-speed card in the Crossfire configuration. Since the 6990 has a core clock of 830Mhz versus the 6970's core clock of 880Mhz, the 6970 will run at 830Mhz if Xfire'd with a 6990. These are the cards stock clocks - even if you overclock both, they will both run at the speed of the lowest card in the configuration.
If you're using three 1920x1080p monitors, your total resolution is 5760x1080. Since you're not running 5760x1200, the performance benefits of the 6990+70 setup aren't going to be fully maximized compared to the GTX580 SLI. If each monitor was 1980x1200, then the 6990+70 would be the clear winner here.
Using this setup is *way* overkill for a HTPC and you'll have plenty of outputs to use it as such. You can also stream content to an Xbox360 or other TV device over a wireless network if you set up Windows Homegroup Sharing or whatever its called.
As for the noise of the 6990, I can't comment as I've never heard/seen one in person. However, according to most reviews of the card, the sound is noticeable. I'm not familiar with water cooling so I can't comment on how much impact that will have on the heat and noise of the card (my assumption is that both would be decreased significantly though).