Anandtech's new article on the current crop of SLI motherb..

Archived from groups: comp.sys.ibm.pc.games.action,alt.comp.periphs.videocards.nvidia (More info?)

.... for those contemplating purchase, or those having any
compatibility trouble with the current Asus A8N-SLI and non-Asus
SLI-video cards ( see the last couple of pages of the review ).
Anand also has very useful advice for first-time SLI-system builders
embedded in this article.

http://www.anandtech.com/mb/showdoc.aspx?i=2358

Some personal observations:-

At the present time, do NOT impulse-buy a SLI MB. Very carefully read
all technical reviews and then wait a few months for production
"maturity".... Ignore all marketing blurb or "gotta-be-first"
inclinations --- you will probably regret it, end up highly frustrated
and/or be a little poorer after extracting yourself from a
self-generated predicament. Also, in the next few months, a much wider
selection will be available, and the later products will have learned
a lot from previous implementation mistakes.

SLI-style PCIe motherboards are here to stay. Remember in non-SLI
mode, you can have (up to) 4-head video out. Highly useful for
artistic and video-production work. Remember also that a SLI MB is
a dual 8x PCIe board, so the extra "video" slot if not used for
video-out could be filled in the future with high-performance
dedicated hardware - say, real-time video-image/animation
processing.......

And the current incremental cost of a SLI-capable MB over non-SLI
(< $30) is miniscule compared to the complete system-build cost.

John Lewis