GeForce 7900GT with 7900GT TOP SLI?

[Bill Cosby]

Howdy partners,

I have an ASUS Geforce EN7900GT TOP graphics adapter, since it is SLI capable, I thought about getting another one of eBay (and the card from a retailer is still pretty expensive).
However the TOP thingy is really rare as it seems, there are a lot of (cheap and new) 7900GT chip based cards for sale though.

I know that I only need the same graphics chip for SLI to work, but my question is, does it still work if the chip is clocked differently?
The TOP model from ASUS has a higher clock rate (70MHz more for the chip and 60 MHz more for memory) than the usual 7900GT models, so would it work to use a normal 7900GT and still be faster than with just my single TOP model?
Or could it come to some nasty slow downs, or wouldn't it work at all?

Thanks in advance.

[deanjo]

Yes, it will work. In such a situation where you have two cards clocked differently, sli will work as if you had 2 cards at the lower speed of the slowest card.

[Bill Cosby]

Yes, it will work. In such a situation where you have two cards clocked differently, sli will work as if you had 2 cards at the lower speed of the slowest card.

Thank you so far.
Do you think I still would gain a considerable burst of speed then?
Or would it vaporize the effect?

[deanjo]

Thank you so far.
Do you think I still would gain a considerable burst of speed then?
Or would it vaporize the effect?

Well that is debatable. Right now there isn't a lot of games in linux that can push current video cards to the point where SLi becomes effective. The most noticeable boost you get with SLi is if you run a newer demanding game and crank up the eye candy to max and set high values of AA and AF in high resolutions. Older, less demanding games see little boost because 1 newer card can easily render them without bottlenecking.


So in short, if the game bottlenecks because of your video card, then yes you will see a healthy boost, if your video card is not your bottle neck the gains are minimal or non existent.

[Bill Cosby]

So in short, if the game bottlenecks because of your video card, then yes you will see a healthy boost, if your video card is not your bottle neck the gains are minimal or non existent.

Thanks again, but I mean, will my faster graphics card then behave like the slower one?

[deanjo]

Thanks again, but I mean, will my faster graphics card then behave like the slower one?

In SLi mode yes. When in sli mode it will match the slower of the cards.

[Bill Cosby]

In SLi mode yes. When in sli mode it will match the slower of the cards.

Sorry to bother you again, but I have to make this clear for me

Will the GC automatically switch between SLI and single mode, depending on load, or is it permanently in SLI mode if I connect the two cards?

Thank you very much, and I hope this will be my last question

[deanjo]

Sorry to bother you again, but I have to make this clear for me

Will the GC automatically switch between SLI and single mode, depending on load, or is it permanently in SLI mode if I connect the two cards?

Thank you very much, and I hope this will be my last question

In the current nvidia blobs, if you have it set to auto, sli will not function (Known bug, in the drivers that should be fixed relatively soon according to nvidia) so if you want to use sli you have to specify the sli mode (SFR or AFR) in your xorg.conf to force it to run in sli mode. When doing this, your 2d clock speeds are uneffected on your on a plain desktop. When firing up a openGL 3d game though your cards will be running effectively as two of the slower card in SLi mode.