Our Take

It really did not come as a surprise that nForce4 Ultra and nForce4 SLI are the same chipset with some capabilities in Ultra turned off. We have seen many cases over the years in which a manufacturer has one CPU-die or one chipset come off a production line, which are then differentiated with laser cuts or some other means of controlling speed or capabilities. What did come as a surprise is how very easy it is to reverse the process - to turn the nForce4 Ultra into the higher-priced and better-performing nForce4 SLI. This is an extremely easy mod for almost anyone.

We suspect that there is more to the story, however, than just the fact that the chip can be modded to be seen by the system as being an SLI chip. nVidia design specifications actually dictate a different board design for Ultra than for SLI. We stated early in this article that DFI is using the exact same board for their SLI and Ultra versions of nForce4. We know that the mod works on the DFI LANParty UT nF4 Ultra-D, but we did not have any other dual video slot Ultra board on which to test the SLI mod. We are expecting the Epox board any day, and we will certainly let you know if the SLI mod works on that board too.

The other surprise is how very close the x16/x2 dual video mode is in performance to the nVidia specified x8/x8. Performance ranged from a worst case of 88.8% of "true" SLI in Half life 2 1600x1200 4xAA/8xAF to slightly better than "true" SLI performance in Far Cry. These numbers are good enough that you can understand why MSI, DFI, and Epox were all planning to release dual-video boards based on the nForce4 Ultra chipset. With nVidia doing everything that they can in Forceware drivers to disable support for Ultra SLI, we can also well understand the reluctance of many manufacturers to try to bring Ultra SLI boards to market.

The discovery that the Ultra chipset can be easily modded to SLI removes a major obstacle to SLI performance on the cheaper Ultra boards - if the manufacturer made provisions for SLI. Once the SLI mod is complete, the system and nVidia drivers see the chipset as a full SLI chipset. This removes the driver issues and the ability of nVidia to turn off support in "non-complying Ultra SLI chipsets".

The DFI LANParty UT nF4 Ultra-D will sell for about $140. With the simple mod, it is a fully capable nF4 SLI motherboard. As you will see in our upcoming reviews, it is also one of the most enthusiast-friendly boards to land on the market since the DFI Socket 754 motherboard. For now, the only board that we know which can be fully converted from Ultra to SLI is this DFI LANParty UT, but there are others on the way, and we are sure it will not be the last. As new Ultra boards with dual-video capabilities arrive, we will let you know if they are up to the conversion task.

When we first found out that an nF4 Ultra could be morphed into an SLI, we felt like kids in a candy shop. The feeling was much like the discovery almost 2 years ago when the Intel 865 chipset could have PAT enabled, so it performed like the 875. In this case, the payoff could be on the order of 25% to 80% performance increase with full SLI compared to single video card performance - much better than the few percent performance improvement that made PAT the must-have feature on 865 boards.


Far Cry: x16 vs. x16/x2 vs. x8/x8 (nVidia SLI)
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  • PrinceGaz - Friday, January 21, 2005 - link

    What gets me is that SLI is still viewed by so many people as a "cheap upgrade path" for their graphics later on, and they use that to justify and SLI (or possibly a modded Ultra board).

    Has everyone who comments here forgotten that there is the option of selling your 6600GT when you fancy an upgrade, and buying a second-hand 6800GT to replace it? I think you'd find the upgrade cost from the 6600GT to 6800GT would be less than a new 6600GT would cost you, regardless of how much prices on new cards fall. The 6800GT will also outperform two 6600GTs in almost all games, especially at higher resolutions and quality settings.

    Even if the second-hand price difference between the 6600GT you want to sell, and the 6800GT you'd want to buy isn't smaller than the cost of a new 6600GT; there's still the question of what are you going to do with two outdated 6600GTs when it's time to do a proper upgrade. Single 6600GT cards will be going dirt cheap because they'll be considered low-end, and nobody would buy two of them when much better single card solutions are available. A 6800GT will at least have some reasonable second-hand value still.

    The only possible reason for seeing SLI as a viable upgrade option is if you're afraid of buying or selling stuff second-hand. In that case you're missing out on a lot of bargains.

    SLI should only be considered by people buying 6800's, either both of them at once or the second within a few months. Considering the cost involved, they'd be fools to save a few dollars and hope the Ultra->SLI mobo hack works correctly for them.
  • crash - Friday, January 21, 2005 - link

    #73 and it will all be moot because you won't have the bridge connector. You will either have to make your own or buy one from someone else. Either way, the cost will reach or exceed what you would've spent had you purchased the SLI board in the first place.
  • AtaStrumf - Friday, January 21, 2005 - link

    Some people still don't get the point of SLi. It's in the cheap, gradual upgrade path.

    This hack, if nVidia doesn't disable it -- driver support in case of SLi is extremely important - new games will require new drivers!!!, makes this an even better deal for the cheap bastards among us, because you only pay a slight premium for being able to cheaply uprage later on (66(8)00GT will be much cheaper when I buy a second one) instead of having to first cash out big time for an SLi mobo just to get into the SLi game.
  • MarkM - Thursday, January 20, 2005 - link

    #65, #66 - what is wrong with nVidia marketing different performance levels. Why do you feel you need to single them out for your wrath? Do you think the CD/DVD for Microsoft's OfficePro costs any more to burn than the one for their OfficeStanderd? Do you get mad at AMD preventing you from increasing the multiplier on their A64 chips?

    Sheez, it's a common buriness practice, everyone does it. If it let them lower their unit cost by producing both chipsets on the same line instead of needing different ones, then bully for them.
  • ChineseDemocracyGNR - Thursday, January 20, 2005 - link

    #63, I don't think you will be able to buy the 3D1 card without Gigabyte's SLI motherboard.

    I have two comments:
    1) in your future benchmarks of SLI products could you add some games that may not have been optimized by nVidia? I don't think most people know about this: http://www.pcper.com/article.php?aid=99&type=e...

    2) Maybe the nForce4 and nForce4-4X can be modded to add SATAII and the other features of the Ultra chipset?
  • bupkus - Thursday, January 20, 2005 - link

    #69 - My only suggestion is if you see the SLI board price as just too high for the initial introduction, the price drop over the next year will subsidise your next upgrade assuming it will be atleast a year until you go for a new video card. Of course what will be is just a guess.
  • OriginalReaper - Thursday, January 20, 2005 - link

    It's already $800-1000 on the 2x GPUs, I think spending a little extra for a the nV SLI x8/x8 is worth it over the Ultra SLI.

    Not that I'd want either solution at the moment.
  • bupkus - Thursday, January 20, 2005 - link

    Consider also, you can buy an SLI capable display adapter today with a non-SLI motherboard. In a year when you may want to upgrade your video by buying a twin you may also be considering a new, dual core CPU.
  • Live - Thursday, January 20, 2005 - link

    To all of you who does not see the point of this mod:

    The point as I see it is not to buy 2 * 400$ cards and then skimp on the motherboard. This is for the ones who can’t afford SLI today. Buy this motherboard and your SLI ready if and when cheaper cards are out or your preferences/financial situation changes.

    I'm one of those people that hold on to my parts for at least 2 years. So it’s nice to know I have as many options in the future open to me with a board like this.

    My bet is that SLI with dual core CPUs and games that are multithreaded and SLI ready from the get go like perhaps Unreal 3 or Far Cry 2 will make SLI look rather tempting.

    Imagine playing Duke Nukem Forever which will come ...heh never mind ;)
  • bupkus - Thursday, January 20, 2005 - link

    #65 - Tell nVidia to "stuff it" and wait for the X800XL. Look people, we all did just fine before SLI and we can do fine without it. Corporations just love it when we are so convinced that we need something they sell that we call them names for taking advantage. Just don't buy into it.

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