Why does SLI need two cards from the same manufacturer?

[HeroOfPellinor]

Just curious what the reasoning for that is.

 

[Fuel Injected]

To minimize problems on the user end, too many variables with video cards from diferent companies(like different core clock speeds)

 

[mwmorph]

it's aminly needing the same biso so they can communicate on the same page.

 

[hans030390]

just a random though, if two cards using SLI are at different speeds (and i know they render half a screen) does one half go faster then the other in framerate?

 

[cbehnken]

Originally posted by: hans030390
just a random though, if two cards using SLI are at different speeds (and i know they render half a screen) does one half go faster then the other in framerate?

SLI will force them to run the lower of the two speeds so this doesn't happen.

 

[AristoV300]

It is just like running 2 sticks of memory.

 

[leedog2007]

Rollo would know for sure, but I don't think you can mix and match the graphics cards.

 

[intogamer]

its like memory and raid

 

[imported_Hi]

i think its because the cards bios are set to communicate with another of the same model
making a card have to work with many cards could be bad for it

 

[Heinrich]

In this thread I was told that it was ok to run 2 different manufacturers as long as the hardware (dvi ports, tv-out) and BIOS were the same

http://forums.anandtech.com/messageview...&STARTPAGE=1&FTVAR_FORUMVIEWTMP=Linear

 

[Acanthus]

Originally posted by: intogamer
its like memory and raid

Only you get an 80% performance increase...

 

[Acanthus]

Originally posted by: Heinrich

In this thread I was told that it was ok to run 2 different manufacturers as long as the hardware (dvi ports, tv-out) and BIOS were the same

http://forums.anandtech.com/messageview...&STARTPAGE=1&FTVAR_FORUMVIEWTMP=Linear

I know a few people that wound up with 2 different manufacturers and just flashed both to Gainward GS bios. Worked fine.

 

[Heinrich]

MY XFX died and was returned - VERY promptly, within about 10 days, and I live on the OPPOSITE coast (VA Beach, VA vs California). Anyway, it works great now by itself. The eVGA that I have has the same BIOS. I switched the 6 jumpers (ridiculous) on my DFI Lan Party NForce4 SLI-DR and used the little bridge chip. Both cards use 5.40.02.36.08 even though the sticker on the XFX says .09 (I checked with nvflash.)

I see a picture all the way through WINDOWS then I see black.

 

[Ronin]

In order for SLi to work properly, the cards have to be able to sync and distribute the data between them (via both hardware and software). Mixing parts in doing so creates confusion by the hardware, and the software, and thus will not work.

 

[Heinrich]

Interesting comment - that's different from many other stories (including success stories) on this board.

 

[ddogg]

i guess it mainly has to do with different BIOSes on the 2 different cards. i want to see how ATI's multi VPU functions. i highly doubt though that they would be able to use different cards on it although i may be wrong!!

 

[Jeff7181]

Originally posted by: ddogg
i guess it mainly has to do with different BIOSes on the 2 different cards. i want to see how ATI's multi VPU functions. i highly doubt though that they would be able to use different cards on it although i may be wrong!!

I think they're saying you will be able to use different model cards... the load will just be split between them... so one card might be rendering 70% of the screen while another renders 30%.

 

[trinibwoy]

Sure looks that way

http://www.hexus.net/content/reviews/review.php?dXJsX3Jldmlld19JRD0xMTY1

Sounds a lot more complicated than SLI with the need for a master and slave boards where the two are not interchangeable. But it will allow the use of different types of cards and may even need a dongle similar to Nvidia's little connector.

 

[fstime]

To minimize problems do what my friend did.

He took a Gigabyte and Leadtek 6600gt and flashed them to the same bios.

Problem fixed.

 

[Heinrich]

I have backed up the XFX 6800 Bios and flashed it onto the eVGA card. No luck. Black screen. CRT says "invalid frequency." Im going to try going to safe mode and downloading drivercleaner and wiping the drivers out and reinstalling them. I've put a little more time in this than i intended to, I may just give up and put the XFX up for sale and buy a 2nd eVGA.

the eVGA (with the xFX bios) is completely happy on its own.

 

[Lonyo]

Originally posted by: Acanthus

Originally posted by: intogamer
its like memory and raid

Only you get an 80% performance increase...

I think maybe he meant in terms of needing 2 the same, or they default to lower speeds.
Oh, and RAM gave give a large speed boost too.

 

[ddogg]

Originally posted by: trinibwoy

Sounds a lot more complicated than SLI with the need for a master and slave boards where the two are not interchangeable. But it will allow the use of different types of cards and may even need a dongle similar to Nvidia's little connector.

lol ya...this master, slave thing is making it look really complicated!!! nvidia SLI is so far good...but who knows ATI might surprise us all with a better way to working with multi-GPUs