Architecture

There was a great deal of talk about why architectural decisions were made, but we will concern ourselves more with what exists rather than why this path was chosen. Every architecture will have its advantages and disadvantages, but understanding what lies beneath is a necessary part of the equation for developers to create efficient code for any architecture.

The first thing of note is NVIDIA's confirmation that 3dcenter.de did a very good job of wading through the patents that cover the NV3x architecture. We will be going into the block diagram of the shader/texture core in this description, but we won't be able to take quite as technical a look at the architecture as 3dcenter. Right now, we are more interested in bringing you the scoop on how the NV36 gets its speed.

For our architecture coverage, we will jump right into the block diagram of the Shader/Texture core on NV35:

As we can see from this diagram, the architecture is very complex. The shader/texture core works by operating on "quads" at a time (in a SIMD manner). These quads enter the pipeline via the gatekeeper which handles managing which ones need to go through the pipe next. This includes quads that have come back for a second pass through the shader.

What happens in the center of this pipeline is dependent upon the shader code running or the texturing operations being done on the current set of quads. There are a certain few restrictions on what can be going on in here that go beyond simply the precision of the data. For instance, NV35 has a max of 32 registers (less if higher precision is used), the core texture unit is able to put (at most) two textures on a quad every clock cycle, the shader and combiners cannot all read the same register at the same time, along with limits on the number of triangles and quads that can be in flight at a time. These things have made it necessary for developers to pay more attention to what they are doing with their code than just writing code that produces the desired mathematic result. Of course, NVIDIA is going to try to make this less of a task through their compiler technology (which we will get to in a second).

Let us examine why the 5700 Ultra is able to pull out the performance increases we will be exploring shortly. Looking in the combiner stage of the block diagram, we can see that we are able to either have two combiners per clock or complete two math operations per clock. This was the same as NV31, with a very important exception: pre-NV35 architectures implement the combiner in fx12 (12 bit integer), NV35, NV36, and NV38 all have combiners that operate in full fp32 precision mode. This allows two more floating point operations to be done per clock cycle and is a very large factor in the increase in performance we have seen when we step up from NV30 to NV35 and from NV31 to NV36. In the end, the 5700 Ultra is a reflection of the performance delta between NV30 and NV38 for the midrange cards.

If you want to take a deeper look at this technology, the previously mentioned 3dcenter article is a good place to start. From here, we will touch on NVIDIA's Unified Compiler technology and explain how NVIDIA plans on making code run as efficiently as possible on their hardware with less hand optimization.

The GeForce FX 5700 Ultra Compilation Integration
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  • Anonymous User - Thursday, October 23, 2003 - link

    All I can say is good-bye and good riddance to Anandtech. HardOCP cleaned up their act. It's time for a house cleaning here.

    Delete ...
  • Anonymous User - Thursday, October 23, 2003 - link

    Alrighty, #7 I really hope that you don't trust those numbers you posted and would discount anything of that nature as pure BS after seeing the graphs.

    (e.g. Some of the differences in the performance of all the cards was less than 10 percent on many of the DX8 test, and your percentages are incredibly ludicris...I dunno, maybe your ATI renders funny graphs)

    The point is that nVidia has finally released a card that is competitive and in some cases superior to other technology. Derek isn't saying "nVidia wins", but more like "nVidia is finally starting to come around." The Final Word comments are strictly by his experience, do you have one of these cards? will your opinion of the IQ differ from mine?

    I think the greatest comment and truest is the one posted in all of the latest graphix card articles: "Wait until your game comes out to buy a new card". It seems like all the lemmings out there are so anxious to throw away there money to have the fastest thing on the market that they seriously get their feelings hurt by the prospect that what they want may not be the best. As an nVidiot myself, I am glad to see the Geforce line of cards starting to come around and admit that the Radeon 9700 Pro is definitely the greatest piece of hardware created since the Geforce 3 quite a few years ago. I am glad both companies are staying competitive, but will always root for my favorite team.

    Make no mistake, fuzzy math is about as logical as strategery. And some of you guys really need a life.

    -The Ways
  • Anonymous User - Thursday, October 23, 2003 - link

    #49, i hate to tell you but basically all optimizations and new filtering methods only apply to FX cards
  • Anonymous User - Thursday, October 23, 2003 - link

    The message is clear--
    Oh, wait, it's not. I personally like nVidia's products, and am leery to jump to ATI, because I've heard lots of horror stories about the Cats completely screwing up a system. Yeah, I know that the Dets are supposed to be "Cheatenators" if you listen to fanATIcs, but I haven't had any complaints about my gameplaying using my overclocked Ti4200 in Halo, UT2k3, or Max Payne 2...
    I'm glad to see nVidia pushing out a decent DX9 midrange card, but I'm not glad to see it not taking the performance crown and almost LOSING to a card that's a full generation behind it in API support!! Not to mention that the 5700 will be obsolete and pretty much bargain basement by the time the games that matter in DX9 come out, like HL2 and Doom3...
    So, the message is NOT clear. The winner remains to be seen, because this review is not finished, nor is the 5700 the last card nVidia's ever going to make. When we see NV40 and R420, then we can talk about the message being clear. Until then, it's all very fuzzy and dependant on which company you trust more... Well, that and how cheap the card is. :P
  • Anonymous User - Thursday, October 23, 2003 - link

    Did anyone else notice in the Nvidia PDF that the Det 50's offer AMD64 support? This sounds to me like it can work in a 64bit operating system. Am I wrong about this? It says it on page 19 of the PDF.
  • Anonymous User - Thursday, October 23, 2003 - link

    #45 it would be simple. when you click on an image to compare, just make the images pop-up in a little box, kind of like this comments box.

    also, maybe instead of making a conclusion at the end of the review, it might have been better to say "to be continued" or something like that.

    i kind of agree with what others are saying, how can you recommend something if you have only run half the tests so far...? seems like the conclusion came a little premature...

    what happens if ati comes out on top in the 2nd round of iq tests?

    will the recommendation get flip-flopped?




  • sandorski - Thursday, October 23, 2003 - link

    It's nice to see Nvidia competing on performance again. However, these visual anomalies and jerkiness gives pause.

    Re Final Word: It seems rather odd that such statements would be made after the first part of a 2 part review, especially when the first part brings up some potentially serious issues that the second part will examine further.
  • Anonymous User - Thursday, October 23, 2003 - link

    #43

    uhm... tell me how Derek can do that? when the screen real estate is obviously taken over by those funky ads ;) No way! sponsors first! they paid for that space. We just have to learn to squint. those graphs look colorful though, i might add.

    even if the game stutters when i play or i see artifacts i will sure be reminded by those graphs and continue to be inpired. wooohoooooooooooo!
  • Anonymous User - Thursday, October 23, 2003 - link

    The 5900 non-ultra at $220 looks like a better deal.

    http://www.newegg.com/app/ViewProduct.asp?descript...
  • Anonymous User - Thursday, October 23, 2003 - link

    I don't think it's right to make any recommendation unless IQ and Framerates are taken into consideration. And not the little bitty screenshots that I had to squint at from the last review.

    Derek, it would help if you made the screencaps larger, and made them animated so that the differences could be seen. For instance, someone put the images you used for that F1 Racer sim in a gif. Looking at the images side by side for the 51.xx drivers, the 45.xx drivers, and the ATI 3.7 drivers, I couldn't see a difference.

    However, once the animated graphic was made, the difference was EXTREMELY apparent that the 3.7 and 45.xx drivers were heads above the 51.xx drivers. Yet in your conclusion you said that there were no palpable differences between the graphics.

    I think what people are trying to say is that you guys can do better than this, and we expect that from you. I know I certainly do.

    Regards,

    Long time AT reader

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