SLI vs Crossfire

[wescrock]

I'm sure that this has been posted before... but i'll ask anyways... i know how the setup of the two differs (SLi is a bridge and Crossfire is a cord out the back) but can somebody explain the difference in performance... im sure its going to be like the difference between Hyper-Threading and Hyper-Transport... thanks
Wes

 

[Dresden]

(scratch my head) they pretty much perform the same. the way the two cards split up and render pixels in a given frame can differ though. ATI has more options when it comes to this, which is why a crossfire system doesn't need driver support to run a game. With Nvidia, this is the case, but Nvidia has had it's SLI out for so long, that it has more features.

I'm pretty sure tomshardware has a past article about the difference, just dig around a bit.

 

[dhlucke]

I would say the biggest difference is that CF only does up to 1600x1200 which pretty much kills those of us with big LCD's.

 

[RichPLS]

That is only true with the X800 series and in CF config only,I believe. Single cards can push a 2405FPW.
Could not imagine that being with problem the x1800 series.

 

[Action_Man]

That is correct. X1000 CF goes up to 2048* 1600 @ 85HZ. CF also has supertiling which seems better then the other rendering modes.

 

[godlyatheist]

SLI can only work with identical cards and you obviously need SLI chipset. A SLI bridge is required too. There's only one rendering option which is screen splitting, but you can assign how much each card handles (e.g. 30-70, 40-60)

CF is more versitile but like people said is limited by screen resolution. I know three options for the CF rendering:
1. 50/50 of the screen-cannot be changed
2. frame by frame--> each card handles one frame
3. random pixels-each card takes on random number of pixels in the screen

CF needs an external cable to connect both card in DVI slot only. So for dual screen both cards must have dual-DVI. You CAN use different CF cards like X800 series and X1000X series, just a "master-slave" situation. Also, catalyst allows you to tweak with the rendering stuff.

Anyone please correct my mistakes

 

[Action_Man]

With the 80 series of nvidia drivers you can use different brand cards.

Also the third rendering option of supertiling divides the board into a chess board and one does white and the other does black.

 

[RichPLS]

nVidia's website says the 7800GTX can only be used on identical 7800GTX. [/shrugs]

 

[Action_Man]

Link 1

"Mixed vendor support for NVIDIA SLI."

Link 2

"New Flexibility:
Mix and Match Graphics Cards from Different Manufacturers
Example: You can use a GeForce 7800 GTX from manufacturer ABC with a GeForce 7800 GTX from manufacturer XYZ."

How reliable it is another thing though.