Multi-monitor SLI Users Rejoice!

Hey guess what? If you've got SLI and two monitors, you no longer have to turn SLI off to use both monitors. It's been 4.5 years since the introduction of SLI and we finally have support for a feature that should've been there from the start. Granted AMD/ATI/SnowWhite didn't have support for this multi-GPU/multi-monitor setup until last year with the Radeon HD 3870 X2 so it's not purely a NVIDIA thing. If you run a full screen 3D application your second display will go blank and come back as soon as you've quit your application, whereas in the past you had to go into the NVIDIA Control Panel, enable SLI, run your 3D app/game, go back in, disable SLI and then you'd get your second display back. In the new driver you don't have to do any of this - sweet.

While NVIDIA's driver supports up to 6 monitors, for SLI to work you can only have displays connected to the master card in SLI with a maximum of two monitors connected. So if you want to have more than 2 monitors and support SLI you'll either need three cards or you will still need to disable SLI to get your non-master SLI card to output video.

The multi-monitor driver interface also got an update in a very sensible way; you can now select which monitor will receive the display when running in SLI mode, it's no longer tied to a fixed output on your video card. Hooray for flexibility!

While selecting the SLI Focus Display is done in the SLI settings menu, when adjusting your multi-monitor setup, there is an indicator that lets you know which display is the SLI focus display. It's a little green square in the corner. Check it out.

When we played around with it, the primary display had to be the SLI Focus Display when the primary display was connected to the SLI bits. The only way to make the primary display (the one with the start menu and all that stuff) not the SLI Focus Display was to run it off a second card. At which point, the SLI Focus Display could still be selected if two monitors are connected to the SLI hardware.

Another multi-monitor feature to note is that 3 games (Flight Simulator X, World in Conflict and Supreme Commander) are also accelerated across multiple monitors. We would really like to see all games supported across multiple monitors (without the use of one of Matrox's DualHead2Go or TripleHead2Go boxes), but there are still some difficulties with rendering a game across multiple displays when the game does not expect to have its framebuffer split. It is good to see that NVIDIA is at least extending support of new features in new drivers to games whose developers have specifically included multiple monitor support.

The extensiveness of the SLI and mulit-monitor flexibility is nice, and we are definitely glad to finally have all of this working. It's been a long time in coming, but we are glad that it's finally here.

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  • chizow - Thursday, November 20, 2008 - link


    We'll certainly see after we run all the tests, but stay tuned for an update on that area.

    When are we going to see an updated, comprehensive review? You mentioned something about a huge review with the new Core i7 test bed over a month ago and the NDA on i7 was lifted over two weeks ago. Still no update or comprehensive GPU review.

    You guys have been making a lot of half-assertions and assumptions promising follow-ups but have consistently failed to follow through on them.
  • CPUGuy - Thursday, November 20, 2008 - link

    I find it odd that someone can admit that both camps have their driver problem yet so asphyxiated on camp's problems more so then the other. When both camps are examined in a petri dish under a microscope it becomes apparent that both camps have their share of problems that effects everyone. Not just the consumers from one camp vs another.

    In all that's why we love to read articles & reviews that are fair and equitable. Which seeks the truth in a unbiased fashion that provides not only truth from just one side but from "both sides" of the coin. Not to be vague:
    -if a driver improves performance, provide picks to show IQ
    -if one card is faster then another, let it do so from it's original standard clock rate.
    -if one card is faster then another overclocked, let both opposing cards show the same percentage of overclock

  • CPUGuy - Thursday, November 20, 2008 - link asphyxiated on one camp's problems more so then the other...
    -if a driver improves performance, provide photos to show IQ
  • GaryJohnson - Saturday, November 22, 2008 - link

    ...asphyxiated ...

    I think the word you were looking for is fixated.
  • poohbear - Thursday, November 20, 2008 - link

    you guys looked at crysis and oblivion and other games that were'nt even mentioned by Nvidia when downloading the drivers. The games nvidia mentions are:

    Up to 10% performance increase in 3DMark Vantage (performance preset)
    Up to 13% performance increase in Assassin's Creed
    Up to 13% performance increase in BioShock
    Up to 15% performance increase in Company of Heroes: Opposing Fronts
    Up to 10% performance increase in Crysis Warhead
    Up to 25% performance increase in Devil May Cry 4
    Up to 38% performance increase in Far Cry 2
    Up to 18% performance increase in Race Driver: GRID
    Up to 80% performance increase in Lost Planet: Colonies
    Up to 18% performance increase in World of Conflict

    I personally noticed a smoother framerate in World in Conflict & Crysis warhead on my 8800gt. Company of Heroes opposing fronts didnt seem to play any different, but the others were definetly smoother. Just my 2 cents.
  • Spacecomber - Thursday, November 20, 2008 - link

    Download and install a new video driver? If the games you are playing are supported, as well as any extra features that you need, I don't see any advantage to jumping on-board with every new driver release.

    I usually wait until I've picked up a new game that reveals some limitation in the driver or until I've upgraded to a new graphics card. Driver releases primarily seem to focus on better supporting the latest games and providing drivers for the latest generation GPUs. Occasionally, you'll see new features introduced, like better support for running two video cards while using one for PhysX acceleration, as in this driver release. However, that seems to be the exception, rather than the rule, which perhaps justifies Anandtech's write-up on this particular driver release.
  • The0ne - Thursday, November 20, 2008 - link

    For what you're saying people should then head over to or use omega drivers that other users have tested on specific games. I'm running 174/175 on mine right now simply because it doesn't choke on the dual display output to my TV, doesn't lag it and is pretty stable with general tasks. I can't say much in terms of games because the only one I play is FFXI and it really on suffers under Vista.

    However, not a single driver package is perfect as their will always be some issue waiting to surface. Just take that to heart when trying different versions.
  • StillPimpin - Thursday, November 20, 2008 - link

    I am very interested to know if dual monitor SLI support is/will be enabled on the next round of Quadro drivers or is this only related to the Geforce line? Reply
  • pmonti80 - Thursday, November 20, 2008 - link

    A little bit off topic, but:
    In what kind of motherboards will you be able to use PhysX SLI? Will there be the same limitations than with normal SLI? (only half of Nvidia chipsets support it; on x58 boards SLI only is available on 9800 GTX or more)
    Which card is the minimum for Physx SLI?
  • chizow - Thursday, November 20, 2008 - link

    PhysX SLI can be enabled on any chipset with multiple PCIE x16 slots, even ones that don't support native GPU SLI. I believe all cards beginning with the 8800 series supports GPU-accelerated PhysX. Reply

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