What are the rules/parameters for selecting 2nd gfx card for SLI?

[BonzaiDuck]

I "did" SLI once, when I got a bundle deal on two identical graphics cards.

Never looked into the limits on selecting a second graphics card -- if it wasn't the same make and model.

I currently have an ASUS GTX 780 "DC2OC-3DG5:"

http://www.newegg.com/Product/Produc...82E16814121779

Not that this is a choice, or that I'm going to "proceed to checkout" today, but could this card be paired with this one? --:

http://www.newegg.com/Product/Produc...82E16814121869

or perhaps a 780"ti"? Or even an eVGA GTX 780 card?

Obviously, the best choice would be the same, identical card. But I'm curious about this.

 

[VulgarDisplay]

Nvidia requires the cards to be the same. Brand doesn't matter as long as it is the same type of card. So you need another gtx780 to pair with your existing card.

AMD allows asymmetric pairing of cards as long as they are of the same performance class. So you can pair a 7970 and a 7950, or a 7870 and a 7850. The trade off is being limited to the speed of the slower card.

I'm unsure if you can do asymmetric crossfire with the new xdma bridge on the Hawaii cards.

 

[Deders]

Like VulgarDisplay says they need to be the same type, so 780TI is out.

Also the fastest card will clock itself down to the same speed as the slower card, so you might as well go for the identical card, unless you really want to watercool the posedion (which is what it is designed for ultimately)

You could go for a different brand like EVGA so long as the type of card is the same.

 

[guskline]

Get 2 identical cards and be done with it!

 

[BonzaiDuck]

Get 2 identical cards and be done with it!

I'm so glad folks got back to me about this.

I'm investigating my options as time passes. Eventually, my ASUS 780 card won't be available, so I wanted to plot out some options. Depends on whether I come to a quicker conclusion as to whether it's worth it. This also has implications for a machine I want to build next year, since I'll be able to split an existing SLI setup as I go through the "building and tuning" phases. More specifically, next year's machine isn't currently destined to be anything other than an "E" hex-core. So I'll need to buy another graphics card anyway.