Judging by this article http://www.anandtech.com/video/showdoc.aspx?i=2284 SLI 6600GT's consistantly outperform a single 6800GT (both on the same mobo) by a good margin. However, when AA and AF are turned up, the 6600GT's lag behind, probably because of their smaller bandwidth. With these stats in hand, how would you expect a 6800GT in a slower nforce 3 mobo and an AGP8X slot to do against SLI 6600GT's in nforce 4 and pci-e? Thanks again for listening. This being said, I am faced with a dilema. The 6800GT pci-e is a better card for most applications, and I could conceivably upgrade it to dual 6800GT's farther down the road. However, dual 6600Gt's perform very well, and it is my guess that they will be able to handle most applications for quite some time, not to mention the fact that I have not seen a pci-e 6800GT priced at lower than 480, compared to around 360-400 for dual 6600GT's. I figure by the time I have enough money to buy another 6800GT, there will be some newer high end cards out and I will want to replace it. For these reasons I am currently leaning towards an SLI 6600GT setup. Any advice is welcome!

i think u can choose SLI
my english is very poor(i'm from china.so...-_-~,but i think i have got your mean)
u buy two sli cards,and when the newer high cards out......
if u don't have enough money to buy two cards.u can buy one,just replace one,

Ah if I could simply replace one of the cards I would certainly get a single 6800GT now, and a newer card later on. However, SLI only works with cards that have the same amount of pipelines and a similar design. My first and foremost question is still: Will dual 6600GT's on an nforce 4 mobo with a 3500+ outperform a 6800GT on an nforce 3 mobo with a 3400+?

i think the firest one is better.
Choose the new one not to be easy to be eliminated !
nf3 doesn't support sli !
now just nf4 support.

ps:Remember .
there is a easy way to choose .............
Decided by the amount of the money .the more Expensive, the better.
but the problem is .we don't have enough money.so we must choose one.
in chinese 性价比。。。。Performance compares with the price !

sorry , my english is very poor,i think i didn't express it clearly
-_-~~~humm~~~~i'll practice my english hardly and...hardly

Point 1: I don't believe future generations of display cards will be made available for AGP

Point 2: SLI'd 6600GTs will outperform even a 6800 Ultra at some specific aspects of 3D dosplay, but on the whole I would consider that the performance of SLI'd 6600GTs would be on a level with that of a 6800GT (or thereabouts, anyway). It also remains to be seen what an NForce4 motherboard with dual PCIE display card slots will cost. Not every NForce4 motherboard will have the dual slots for SLI, remember!

Point 3: Comparisons between AGP and PCIE are perhaps misleading at present. The peformance benefits of PCIE are mainly in software, and current games do not make use of the extra bandwidth which PCIE potentially has available. While performance might be comparable now, there's no guarantee that it will remain comparable for future 3D games.

So what to do? I'd be grabbing the 6800GT system now, if I could afford it, and worrying about all the new technology when time comes for the NEXT upgrade. But then I work on a limited budget, and try to build systems cheaply and upgrade them more often. Stay one step behind technology and you always get adequate performance at the cheapest cost, I believe ;)

Yep that's the way I've gone until now, but I decided just to go for a good high end system this time ;)
I'll see if I can afford a 6800GT pci-e board. A high quality SLI Asus mobo(the one they used for the testing on that article) is probably going to be priced at 180, which isn't bad. I just hope the 6800GT pci-e has a nice price drop soon. Thanks for the help

do you think it will still be worth it to get a 6800GT in march or april?

Hell, I don't plan to get one for myself for another YEAR!