What does SLI mean?

[petros]

Have ordered my new computer from Evesham and the Graphics card is an Nvidea 7900 gtx with 512 mb of memory.I notice that in the graphics card benchmark tests this card running in SLI mode is a lot faster than one that isn't.Any one know what this means? In laymans terms that is.

[Bodo]

IIRC this means that you can cluster two graphics cards of the same type for the same result (moving picture on your screen). Think an inline 4cyl. and a V8

[petros]

You mean I need another card if I want SLI ?

[Bodo]

Yes, this is my understanding

[Bodo]

Here are some pictures:
www.neoseeker.com/Articles/Hardware/Features/nvslitesting/

http://techreport.com/reviews/2004q4/

Edited by Bodo on Friday 1st September 22:09

[petros]

Cheers

[[k]ar|]

For extra nerd points...

SLI was originally developed by one of the companies which first came up with the concept of 3d accelerator cards - 3DFX, which was subsumed by nVidia some time ago. Back in the day, you would link two cards together using a series of cables which physically mixed the output from each. At that time, SLI stood for Scan Line Interleave - each card would render alternate lines of the display, thus splitting the load on a fixed equal basis.

Fast-forward to a couple of years ago, nVidia re-introduces SLI - now standing for Scalable Link Interface. This refers to the physical connection between the cards, which in the current generation now talk to each other to either dynamically share the load for maximum efficiency (the system looks at each frame individually, then splits the image in two so that each card takes half the total processing load necessary to render the entire frame). Alternatively, the system can simply cause each card to render alternate whole frames.

...like I said, nerd


[k]

[bez_uk]

I have a Nvidia 7900 GTX (mobile edition but there's little difference)...

Unless you are stupidly picky about graphics... you don't need SLI with that card. I can run most games at 1920x1200 res with graphics set to high. The thing with SLI is that it'll be able to run the same res with more AA and AF (smoother edges and less blurry) while maintaining a higher framerate ie maybe 100 instead on 60.

You only need 60 on most TFT/LCD screen and you only need 30 to have no stuttering!

[thepassenger]

bez_uk said:

I have a Nvidia 7900 GTX (mobile edition but there's little difference)...

Unless you are stupidly picky about graphics... you don't need SLI with that card. I can run most games at 1920x1200 res with graphics set to high. The thing with SLI is that it'll be able to run the same res with more AA and AF (smoother edges and less blurry) while maintaining a higher framerate ie maybe 100 instead on 60.

You only need 60 on most TFT/LCD screen and you only need 30 to have no stuttering!

To be honest, I'm not sure anyone but the most hardcore gamer or perhaps a serious engineer type bod would need 2x or 4x SLI then again do 3Ds Max, Autocad and high end movie stuff make any use of the GFx processing capabilities? As I thought it was all just CPU grunt... hmmm

[Bodo]

thepassenger said:

[quote=bez_uk]

To be honest, I'm not sure anyone but the most hardcore gamer or perhaps a serious engineer type bod would need 2x or 4x SLI then again do 3Ds Max, Autocad and high end movie stuff make any use of the GFx processing capabilities? As I thought it was all just CPU grunt... hmmm

Engineering computing relies on hardware-accelerated OpenGL chips like the Nvidia Quadro which they offer for workstations in SLI mode, too.

[bez_uk]

yes... and on the note the crazy mac pro... with quad core intel zeon, 4x nvidia quadro, 16Gb ram and countless 500GB HDs!!

[thepassenger]

Bodo said:

thepassenger said:

[quote=bez_uk]

To be honest, I'm not sure anyone but the most hardcore gamer or perhaps a serious engineer type bod would need 2x or 4x SLI then again do 3Ds Max, Autocad and high end movie stuff make any use of the GFx processing capabilities? As I thought it was all just CPU grunt... hmmm

Engineering computing relies on hardware-accelerated OpenGL chips like the Nvidia Quadro which they offer for workstations in SLI mode, too.

Thanks for that. I guess it'd be why I always thought it was CPU grunt; never played on a machine with a Quadro or similar card in it.

[Bodo]

thepassenger said:

Thanks for that. I guess it'd be why I always thought it was CPU grunt; never played on a machine with a Quadro or similar card in it.

You won't see a difference in gaming, because games make no use of these special features. The chips, BTW, are the same that Geforce cards use. It's just the driver that enables hardware acc. OpenGL, when it recognizes a Quadro card.
Yes, you could spoof Quadro chipset with an up to Gefroce2 card by just resoldering a resistor, but they put that somewhere into a chip from Geforce 3 on.

[malman]

And then people just started flashing new bioses onto them to turn them into quadro cards

[Bodo]

malman said:

And then people just started flashing new bioses onto them to turn them into quadro cards

I've heard about some obscure driver that enables the Quadro features, but never heard of that BIOS mod. Do you have a link to a HowTo?

[malman]

I read a load of stuff about it in the overclockers forums but can't find a link but here is a softmod (no bios) to make a 6800 GT/ultra into a quadro 4000 but its faster than the quadro

http://forums.guru3d.com/showthread.p

Edited by malman on Sunday 3rd September 22:05

i don't think its possible with the newer cards

Edited by malman on Sunday 3rd September 22:08

I think there are stil bioses knocking about if you want to use this on linux as the softmod relies on windows software

Edited by malman on Sunday 3rd September 22:13

[Bodo]

malman said:

I think there are stil bioses knocking about if you want to use this on linux as the softmod relies on windows software

Edited by malman on Sunday 3rd September 22:13

^^that man knows the game!

[mcflurry]

circa 1999 it was de rigeur to have 2 pci cards doing the graphics, both with 8 or 12 mb of memory, to play doom clones