tbreak have dome some testing to see how the Nvidia GeForce 9800 GTX scales from single use to dual SLI through to triple SLI.
Here’s what they found:
“So there you have it- at the resolutions that we tested these games under, Triple SLI does not really bring much to the table. Out of the eight games, there was noticeable (20% or higher) difference in four- Company of Heroes, Crysis, Enemy Territory and Lost Planet. The other four games didn’t show that big of an improvement.
Also worth noting is that Crysis did not play well with 4X AntiAliasing and Triple SLI. Company of Heroes wasn’t too happy either. However, these are expected driver issues that will be solved sooner or later.
So at the moment, Triple SLI might only be worth for people with displays capable of extremely high resolutions- we’re talking 30″ LCDs here. For everyone else including a high-end gamer that plays at 1920×1200 with 4X AA, your standard dual card SLI is more than capable and the scaling of Triple SLI is not required.”
(full review at http://www.tbreak.com/reviews/article.php?id=607)