SLI Performance

For months, nVidia has been sneaking peeks at their upcoming Dual Video card capabilities, based on a technology known as SLI, or Scalable Link Interface. Not since the PCI Voodoo 2 from 3dfx in 1996 have we seen such a solution from a major graphics vendor. Of course, history saw the original 3dfx die in the market place. The single-slot AGP was introduced, 3dfx lost the video wars, and nVidia purchased what was left of 3dfx.

We have been told that 3dfx engineers had quite a bit to do with the design of the new GeForce 6 series, and that is finally starting to make sense when we see that SLI capabilities are built into the 6 series video cards. Dual AGP would require a custom design, but PCI Express, like PCI in the past, finally provides the kind of platform that nVidia needed to launch a new SLI solution.

While nVidia was not ready to ship nForce4 SLI reference boards for review, they were demonstrating a major manufacturer's nF4 SLI board with a pair of nVidia 6800 Ultra video cards at 1600x1200 resolution at 4x AA. We also got to play with the SLI system with an Athlon 64 4000+ CPU, confirming benchmarks that were supplied by nVidia.

Single GPU vs. SLI - nForce4 SLI
6600GT 6800GT 6800 Ultra
Single SLI % Increase Single SLI % Increase Single SLI % Increase
Doom3 17.3 32 85% 37.9 65.2 72% 42.4 71.7 69%
Halo 37.23 58.58 57% 50.01 72.76 45% 57.21 79.01 38%
3DMark05 3186 5698 85% 4588 8271 80% 5211 9297 78%

Increases in video performance from 38% to 85% are certainly impressive, and there are gamers and performance enthusiasts who will be flocking to the new nForce4 SLI boards as soon as they start shipping in the next few weeks. Perhaps the most impressive gain here is the performance leap with a pair of SLI 6600GT video cards. Two of these less than $200 cards are actually faster in most benchmarks compared to a single $400 6800GT. This provides an interesting upgrade path for many users. Of course, a pair of 6800GT or 6800 Ultra cards take performance to levels that we have never seen before.




Click to enlarge.


Shipping boards will allow a single video card of any brand at x16 PCIe or 2 nVidia video cards in two x8 PCIe slots in SLI mode. The SLI boards can be switched easily from x16 to SLI mode by switching a programming card on the board.



Click to enlarge.


nVidia says that the first nForce4 SLI boards will be available in the next few weeks from Asus and MSI. Other manufacturers will also be supplying SLI motherboards later this year.

The nForce4 Family ActiveArmor: nVidia Secure Networking Engine
Comments Locked

101 Comments

View All Comments

  • suave3747 - Wednesday, October 20, 2004 - link

    #70

    According to nVidia's website regarding the nForce 4 SLI, it states that the board will have 20 lanes of PCIe. It also states that there will be 3 PCIe 1x slots. I assume that the SLI board will have the option of using 1 PCIe 16x and 3 PCIe 1x slots, or 2 PCIe 8x slots and 3 PCIe 1x slots. Therefore, there is really no "lack" of PCIe 1x slots on the board. That board pictured was probably just a poor representation of the actual retail board.

    The thing I am curious to know is whether there will be a reasonable amount of standard PCI slots available for use until PCIe cards for sound and whatnot become more prevalent.
  • stelleg151 - Wednesday, October 20, 2004 - link

    Wesley, now that your done testing the board, if you need someone to take it off your hands I would be willing to take that burden.
  • ThePlagiarmaster - Tuesday, October 19, 2004 - link

    Wesley,

    I'm wondering why the dvd2avi divx 5.1.1 show such close results here. With basically the same machines on hardocp, they show the athlon64 beating Intel's best by HUGE margins (like 20% faster than the 3.6 and almost the same over the 3.4ee)

    http://www.hardocp.com/article.html?art=Njc1LDM=

    You guys showed the same thing no too long ago, but I can't find the article now. The paragraph under the graphs of the A64 winning said Intel lost the last thing they used to win in the benches. The article appears gone? What happened here, why so different from dvd2avi results at hardocp? They used the same divx 5.1.1 so it's not the encoder or the frontend. Heck even the 3500+ dominated the 3.6 and 3.4ee (more than 10%).

    Whatever it is, I think a bit of research needs to be done on what's best for AMD, and what's best for Intel and pit them against each other. Clearly AMD people would run the way hardocp does (though it looks no different than what's used here). While you state you can show whatever you want, perhaps you should be showing the BEST for each platform. Would people really go home and run in a way that makes their cpu look like crap?

    When you're talking about cutting 20% off of encoding, that adds up to a lot of time. I'd argue with the statement about divx 5.1.1 exploiting sse3 and making Intel a usual winner. Hardocp has been using 5.1.1 and A64's kill p4's with it (and have for a long time on their site). Is it AutoGK that throws things out of whack? Does it favor Intel so much that it causes a 20+ percent reversal? If it's truly based on dvd2avi how could it be so far out of whack compared to hardocp's scores? I think your readers would want to know which way to encode the fastest with whichever cpu they choose. Why would people want to know what the middle ground is and lose 20% cpu performance? Maybe Xmpeg for Intel, and pure dvd2avi for AMD?
  • Wesley Fink - Tuesday, October 19, 2004 - link

    #73 -
    The earlier results are on on different test bed with a different video card. If you check out results on the same setup at http://www.anandtech.com/mb/showdoc.aspx?i=2128&am... you will see that the Asus is performing about the same as the other K8T800 boards. It is true that the nVidia nF3 and nF4 perform best with an nVidia card which we have pointed out many times in the past.
  • Saist - Tuesday, October 19, 2004 - link

    just wanted to make a couple of comments:

    Nvidia's Soundstorm was a result of it's partnership with Microsoft and the Xbox. Since Nvidia is no longer being funded by Microsoft and is no longer involved with Xbox2, there is little reason from Nvidia's viewpoint to continue researching audio.

    I also will state that if you are scared of Creative and you want more powerful audio. Get a freaking Via Envy chip. Those are only $20-$30 with shipping and match the Creative Offerings pretty nicely.
  • Saist - Tuesday, October 19, 2004 - link

  • Noli - Tuesday, October 19, 2004 - link

    For all those disappointed with old AC97 codec sound chip on nf4, why not wait for via's K8T890 with better envy sound? (ok it's still not as good as soundstorm but it's better than AC97 right?). K8T890 also should have dual vid cards and also NCQ disk support... (but admittedly lacks ntune style bios extras).

    One thing I want to know is if K8T890 only supports nvidia SLI?? Presume so cause it's branded dual GFX. Would be awesome to be able to double up with less noisy ATI cards though. Also, seem to remember that Alienware's dual card solution was NOT SLI and seemed to produce consistent 90%+ frame rate improvements. Anyone know if/when this is coming out?! If so, 90%+ beats nvidia at their own game (and from a computer 'vendor' - ha!).

    Disappointed that dual vid cards might be limited to nvidia - 6800GTs are good but still prefer ATI and 2 nvidia cards would prob be too noisy for me...
  • Spinne - Tuesday, October 19, 2004 - link

    When will the nTune software be avaiable? NVidia's download site has a page for nTune, but the download link at the bottom still points to the old System Utility.
  • Rza79 - Tuesday, October 19, 2004 - link

    Correct me if i'm wrong but this how i see it:

    First check this review:
    http://www.anandtech.com/cpuchipsets/showdoc.aspx?...

    -------------------

    Check the Business Winstone test scores:
    nForce3 => 30.1
    K8T800 => 28.9

    Now this review:
    nForce3 => 30.1
    K8T800 => 26.9

    ---------------------

    Now Multimedia Winstone:
    nForce3 => 37.4
    K8T800 => 36.9

    In this review:
    nForce3 => 36.9
    K8T800 => 33.4

    ---------------------

    This can't be right?
    If the Asus board really performs this bad, then they should have taken another board.

    It's harder to judge about the gaming test since they use a different card. Above that, Geforce cards tend to perform better on a nForce platform. So my guess is to have a fair review they should have used a ATI based card like the X800.

    Second thing they always forget to mention is the Serial ATA driver for the Via board. I mean this can be an important factor.

    I agree with post nr. 69 & 70.

    Lately i'm starting to lose faith in reviews from Anandtech, just like i did with Tomhardware a couple of years ago. Seems like you can't get reliable reviews with the big review sites anymore.
  • Wesley Fink - Tuesday, October 19, 2004 - link

    #70 -
    We will be rewiewing the K8T890 as soon as we receive a retail board. Thus far none have shipped.

    The K8T890 reviews at other sites in September were based on a traveling preview board which VIA did not make available to all of the major review sites.

Log in

Don't have an account? Sign up now