Dual card SLI vs 1 top-end

My original consideration for my video card is something near the top of the line, a GTX 280 for example
http://www.newegg.com/Product/Prod [...] 6814130492

However the more I read, the more it seems that two cards with an SLI setup is becoming a much more common practice.

Would buying 2 of
http://www.newegg.com/Product/Prod [...] 6814130469
be better performance than the GTX 280 above?

I play WoW primarily with a dual monitor setup, but also will be playing games like Fallout 3, etc

let's assume i'll not be oc'ing, i'm really just looking to find out how viable dual cards that're less-than-cutting-edge would be, compared with a more cutting edge card, given roughly the same total cost

call me a noob but i have no idea what that means

Yes, two 9800GTX+/GTS 250's will be faster than a single GTX 280.
That is not your best option on either front, however.

For one thing, the GTX 280's run way to hot (usually to throttling their speed, sometimes to failure) and have been put to the curb with the release of the GTX 285.
The GTX 285 is quite a bit faster and cooler than a GTX 280 and can be found for not much more.
It is currently the fastest single GPU card out there.
Other great single GPU options are the GTX 275 and 4890.

While dual midrange GPU's will far outperform a single GPU, your choice of an overpriced 9800GTX+/GTS 250 is not very good.
Look into either a pair of 4870 1Gb cards or a pair of GTX 260 Core 216's.
Either setup will cost about the same as a pair of your chosen GPU's and give you much more performance than either of your original choices.

Do not worry to much about micro stutter.
It is a problem that has largely disappeared with the current generation GPU's.
If you are unlucky enough to experience it with a new game, updating to the latest drivers (or the next release drivers) will probably fix it.

Another thing to keep in mind is the power requirements of a decent dual card setup.
You should have AT MINIMUM a quality 550w PSU.
If you have an inferior unit (wattage or brand) look into a new 550w+ Corsair, PCP&C, Seasonic or Antec Earthwatts PSU.

In general, two GTS250s in SLI are gonna be faster than a single GTX280. At current prices though an ever better option would be to spend $20 more to get two of these GTX 260s and run them in SLI

ECS NGTX260-896MX-F GeForce GTX 260
http://www.newegg.com/Product/Prod [...] 6814134075

Well assuming you have a capable PSU to do so anyway.

While I agree with most of the above (except concerns over microstutter, don't worry about that myth) I think since you mostly play WoW I would suggest 2x hd4850 cards. Even if you are playing high resolution two of these will give better performance than a single gtx285, and they can be had for under $100 each. Giving your games of choice this is all you really need....in fact you might be able to get by with just one, depending on your resolutions.

I haven't heard anything about the brand ECS, I've previously tended toward EVGA cards in the past.

Other than a bit higher price ( which puts dual mid-range cards out of my price range, dual ECS brand cards pushes it already) ... what else is the difference? The ECS card seems to be highly recommended, but I'd prefer to stay with something I know.


Edit: with the current sale, the EVGA cards are only $10 more each, minus $5 with free shipping, $10 won't make a difference. As a bonus, Terminator Salvation and COD free x2!