As I understand it adding a second SLI graphics card will only net about 15-30% fps increase for non S-3D gaming.

What about in S-3D? Do the invida S-3D drivers take better advantage of the second card? Should I expect a 50-75% fps increase?

My two options would be to buy two of these for $460

http://www.newegg.com/Product/Product.a ... -_-Product

Or one of these for $350

http://www.newegg.com/Product/Product.a ... 6814121412

The results from this test indicate that two cards are better than one: http://3dvision-blog.com/tag/sli-in-stereo-3d/
On the other hand I've gotten advise that a single card is more reliable and the benefit of SLI is highly game dependent. Then again I've also read that it's entirely driver dependent - which is why I'm here asking this question.

BTW I've been gaming with LCD shutter glasses since 03'. Great stuff, but it's time for a new PC/monitor/glasses.

Yes, Nvidia 3D Vision does support SLI. This is a new addition though, and traditionally there has been bad support for SLI. Other drivers like iz3d and DDD still do not support SLI. Personally, I have not had an SLI system. But from everything I've read SLI can be problematic and is not worth the trouble. I would recommend getting a fast single card solution. The GTX 570 should be a fine choice and should be good for very many games.

Good news is that, 2d SLI runs much worse than 3d SLI !!!!

It has to do with the resolution though, 720p used to be cpu limited, and 3d workload much nicer distributed much more evenly, so it seems. I have constant 60fps in Borderlands with SLI in 3D -> 120.

Once I turn it off I dont have 120 in 2D but 85.

Thanks for the reply guys!

I'm all for a simple, single card solution, but the figures in this benchmark show a dramatic increase in FPS with dual 480's over a single 580.
Am I missing something? All the advise I'm getting is for a single card, but I'm having trouble reconciling this with the bench-test.

http://3dvision-blog.com/tag/sli-in-stereo-3d/

I would say get the GTX 570 now, and if/when it starts to feel slow then get a second 570 for SLI. If you buy the 460's now you are basically stuck with them and if they are not enough then you are SOL.

Getting two 570's would be ideal, but I can't afford it outright, and I'm not much of an upgrader. I tend to keep my PCs as-is for about 5-6 years, then just get a new one.

Looks like a single 580 (which is a faster card then the 570) only nets an 18% improvement in FPS. But dual 480's gets you a 70% increase in FPS.

But you're right, if the 460's don't cut it, I'm SOL except for overclocking...

OK I think I see where the disconnect is.

The benchmarking is for a 480 vs 580, and they are similarly priced cards. The 460 is a cheaper card, so I can't expect two of them to necessarily best a 570.

Wow didnt realize how old this thread was when I replied lol