NVIDIA's Dirty Dealing with DX10.1 and How GT200 Doesn't Support it

I know many people were hoping to see DX10.1 implemented in GT200 hardware, but that is not the case. NVIDIA has opted to skip including some of the features of DX10.1 in this generation of their architecture. We are in a situation as with DX9 where SM2.0 hardware was able to do the same things as SM3.0 hardware albeit at reduced performance or efficiency. DX10.1 does not enable a new class of graphics quality or performance, but does enable more options to developers to simplify their code and it does enhance performance when coding certain effects and features.

It's useful to point out that, in spite of the fact that NVIDIA doesn't support DX10.1 and DX10 offers no caps bits, NVIDIA does enable developers to query their driver on support for a feature. This is how they can support multisample readback and any other DX10.1 feature that they chose to expose in this manner. Sure, part of the point of DX10 was to eliminate the need for developers to worry about varying capabilities, but that doesn't mean hardware vendors can't expose those features in other ways. Supporting DX10.1 is all or nothing, but enabling features beyond DX10 that happen to be part of DX10.1 is possible, and NVIDIA has done this for multisample readback and can do it for other things.

While we would love to see NVIDIA and AMD both adopt the same featureset, just as we wish AMD had picked up SM3.0 in R4xx hardware, we can understand the decision to exclude support for the features DX10.1 requires. NVIDIA is well within reason to decide that the ROI on implementing hardware for DX10.1 is not high enough to warrant it. That's all fine and good.

But then PR, marketing and developer relations get involved and what was a simple engineering decision gets turned into something ridiculous.

We know that both G80 and R600 both supported some of the DX10.1 featureset. Our goal at the least has been to determine which, if any, features were added to GT200. We would ideally like to know what DX10.1 specific features GT200 does and does not support, but we'll take what we can get. After asking our question, this is the response we got from NVIDIA Technical Marketing:

"We support Multisample readback, which is about the only dx10.1 feature (some) developers are interested in. If we say what we can't do, ATI will try to have developers do it, which can only harm pc gaming and frustrate gamers."

The policy decision that has lead us to run into this type of response at every turn is reprehensible. Aside from being blatantly untrue at any level, it leaves us to wonder why we find ourselves even having to respond to this sort of a statement. Let's start with why NVIDIA's official position holds no water and then we'll get on to the bit about what it could mean.

The statement multisample readback is the only thing some developers are interested in is untrue: cube map arrays come in quite handy for simplifying and accelerating multiple applications. Necessary? no, but useful? yes. Separate per-MRT blend modes could become useful as deferred shading continues to evolve, and part of what would be great about supporting these features is that they allow developers and researchers to experiment. I get that not many devs will get up in arms about int16 blends, but some DX10.1 features are interesting, and, more to the point, would be even more compelling if both AMD and NVIDIA supported them.

Next, the idea that developers in collusion with ATI would actively try to harm pc gaming and frustrate gamers is false (and wreaks of paranoia). Developers are interested in doing the fastest most efficient thing to get their desired result with as little trouble to themselves as possible. If a techique makes sense, they will either take it or leave it. The goal of a developer is to make the game as enjoyable as possible for as many gamers as possible, and enabling the same experience on both AMD and NVIDIA hardware is vital. Games won't come out with either one of the two major GPU vendors unable to run the game properly because it is bad for the game and bad for the developer.

Just like NVIDIA made an engineering decision about support for DX10.1 features, every game developer must weight the ROI of implementing a specific feature or using a certain technique. With NVIDIA not supporting DX10.1, doing anything DX10.1 becomes less attractive to a developer because they need to write a DX10 code path anyway. Unless a DX10.1 code path is trivial to implement, produces the same result as DX10, and provides some benefit on hardware supporting DX10.1 there is no way it will ever make it into games. Unless there is some sort of marketing deal in place with a publisher to unbalance things which is a fundamental problem with going beyond developer relations and tech support and designing marketing campaigns based on how many games dispaly a particular hardware vendors logo.

The idea that NVIDIA is going to somehow hide the capabilities of their hardware from AMD is also naive. The competition through the use of xrays, electron microscopes and other tools of reverse engineering are going to be the first to discover all the ins and outs of how a piece of silicon works once it hits the market. NIVIDA knows AMD will study GT200 because NVIDIA knows it would be foolish for them not to have an RV670 core on their own chopping block. AMD will know how best to program GT200 before developers do and independantly of any blanket list of features we happen to publish on launch day.

So who really suffers from NVIDIA's flawed policy of silence and deception? The first to feel it are the hardware enthusiasts who love learning about hardware. Next in line are the developers because they don't even know what features NVIDIA is capable of offering. Of course, there is AMD who won't be able to sell developers on support for features that could make their hardware perform better because NVIDIA hardware doesn't support it (even if it does). Finally there are the gamers who can and will never know what could have been if a developer had easy access to just one more tool.

So why would NVIDIA take this less than honorable path? The possibilities are endless, but we're happy to help with a few suggestions. It could just be as simple as preventing AMD from getting code into games that runs well on their hardware (as may have happened with Assassin's Creed). It could be that the features NVIDIA does support are incredibly subpar in performance: just because you can do something doesn't mean you can do it well and admitting support might make them look worse than denying it. It could be that the fundamental architecture is incapable of performing certain basic functions and that reengineering from the ground up would be required for DX10.1 support.

NVIDIA insists that if it reveals it's true feature set, AMD will buy off a bunch of developers with its vast hoards of cash to enable support for DX10.1 code NVIDIA can't run. Oh wait, I'm sorry, NVIDIA is worth twice as much as AMD who is billions in debt and struggling to keep up with its competitors on the CPU and GPU side. So we ask: who do you think is more likely to start buying off developers to the detriment of the industry?

Derek's Conjecture Regarding SP Pipelining and TMT GT200 vs. G80: A Clock for Clock Comparison
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  • elchanan - Monday, June 30, 2008 - link

    VERY eye-opening discussion on TMT. Thank you for it.
    I've been trying to understand how GPUs can be competitive for scientific applications which require lots of inter-process communication, and "local" memory, and this appears to be an elegant solution for both.

    I can identify the weak points of it being hard to program for, as well as requiring many parallel threads to make it practical.

    But are there other weak points?
    Is there some memory-usage profile, or inter-process data bandwidth, where the trick doesn't work?
    Perhaps some other algorithm characteristic which GPUs can't address well?



    Reply
  • Think - Friday, June 20, 2008 - link

    This card is a junk bond when taking into consideration cost/perfomance/power consumption.

    Reminds me of a 1976 Cadillac with a 7.7litre v8 with only 210 horsepower/3600 rpm.

    It's a PIG.
    Reply
  • Margalus - Tuesday, June 24, 2008 - link

    this shows how many people don't run a dual monitor setup. I would snatch up one of these 260/280's over the gx2's anyday, gladly!!

    The performance may not be quite as good as an sli setup, but it will be much better than a single card which is what a lot of us are stuck with since you CANNOT run a dual monitor setup with sli!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
    Reply
  • iamgud - Wednesday, June 18, 2008 - link

    "I can has vertex data"


    LOL

    These look fine, but need to be moved to 55nm. By the time I save up for one they will .
    Reply
  • calyth - Tuesday, June 17, 2008 - link

    Well what the heck are they doing with 1.4B transistors, which is becoming the largest die that TMSC has been producing so far?
    The larger the core, the more likely that an blemish would take out the core. As far as I know, didn't Phenom (4 cores on die) suffered low-yield problems?
    Reply
  • gochichi - Tuesday, June 17, 2008 - link

    You know, when you consider the price and you look at the benchmarks, you start looking for features and NVIDIA just doesn't have the features going on at all.

    COD4 -- Ran perfect at 1920x1200 with last gen stuff (the HD3870 and 8800GT(S))so now the benchmarks have to be for outrageous resolutions that a handful of monitors can handle (and those customers already bought SLI or XFIRE, or GTX2 etc.)

    Crysis is a pig of a game, but it's not that great (it is a good technical preview though, I admit), and I don't think even these new cards really satisfy this system hog... so maybe this is a win, but I doubt too many people care... if you had an 8800GT or whatever, you're already played this game "well enough" on medium settings and are plenty tired of it. Though we'll surely fire it up in the future once our video cards "happen to be able to run it on high" very few people are going to go out of their way $500+ for this silly title.

    In any case, then you look at ATI, and they have the HDMI audio, the DX 10.1 support and all they have to do at this point is A) Get a good price out the door, B) Make a good profit (make them cheap, which these NVIDIA are expensive to make, no doubt) and C) handily beat the 8800GTS and many of us are going to be sold.

    These cards are what I would call a next gen preview. Some overheated prototypes of things to come. I doubt AMD will be as fast, and in fact I hope they aren't just as long as they keep the power consumption in check, the price, and the value (HDMI, DX10.1, etc).

    Today's release reminded me that NVIDIA is the underdog, they are the company that released the FX series (desperate technology, like these are). ATI has been around well before 3DFX made 3d-accelerators. They were down for a bit, and we all said it was over for ATI but this desperate release from NVIDIA makes me think that ATI is going to be quite tought to beat.

    Reply
  • Brazofuerte - Tuesday, June 17, 2008 - link

    Can I go somewhere to find the exact settings used for these benchmarks? I appreciate the tech side of the write up but when it comes to determining whether I want one of these for my gaming machine (I ordered mine at midnight), I find HardOCP's numbers much more useful. Reply
  • woofermazing - Tuesday, June 17, 2008 - link

    AMD/ATI isn't going to abandon the high end like your article implies. Their plan is to make a really good mid range chip, and ductape to cores together ala the X2's. Nvidia goes from the high-end down, ATI from the mid-end up. From the look of it, ATI might have the right idea, atleast this time around. I seriously doubt we'll see a two core version of this monster anytime soon. Reply
  • DerekWilson - Tuesday, June 17, 2008 - link

    they are abandoning the high end single GPU ...

    we did state that they are planning on competing in the high end space with multiGPU cards, but that there are drawbacks to that.

    we'll certainly have another article coming out sometime soon that looks a little more closely at AMD's strategy.
    Reply
  • KeypoX - Tuesday, June 17, 2008 - link

    i dont like it, not impressed either :(. Hopefully my 8800gt last for a while, far past this crap atleast Reply

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