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
Comments Locked

114 Comments

View All Comments

  • Anonymous User - Saturday, October 25, 2003 - link

    #49

    There are no DX9 cards....They run it via a DX9 wrapper since the native DX9 in-hardware support sucks more than Jenna Jameson on a gang bang movie.

    Horror stories? Like that of Cat 3.8 burning up monitor crap? Give me a break you idiot, I can say the same crap against NV without any proof, yet I lost 2 GFMX with a real bug on Det 6.xx where the speed of the GPU and memory doubled once you got out of Standby mode. Get back to your sandbox kid.
  • Anonymous User - Saturday, October 25, 2003 - link

    ""jesus, fanatics get all pissy if their card loses in FPS tests... you act like every consumer who reads this review will be swayed into believing that NV sells a superior midrange card... its obvious that the "ATI v NV" battle is personal to u... my only question is why? are you guys trying to justify your purchases by bashing something that poses a threat? personally, i dont let hardware sites choose what i buy... i often times purchase 2 contending cards, and take it upon myself to determine which is better... the winner stays in my machine, the loser goes back to where it came from...""



    My own personal reason is to save a few from lunatic flamers like you how post just rage instead of reason to support your standpoint.....pathetic.
  • Anonymous User - Saturday, October 25, 2003 - link

    Yup. HE couldn't do anything about scores (inevitable), so he proceeded to take everything NVidia said for granted (as usual).

    That's like listening to OJ SImpson acussing everyone else of being a murderer.

    DOn't care if there were developers there...ALL HAD WAY BIGGER ISSUES with FX cards and said nothing, but to show a fe selected screenshots on TWIMTBP games, and everyone with some brains knows NVidia pushes for optimized code on that software and/or code that will not work right on the competition.....old news.
  • Anonymous User - Saturday, October 25, 2003 - link

    "#19, I don't think it is a fanboy thing. It's an AT thing that's costing them their respect from other hardware sites and readers."


    Wiser words are yet to be spoken.
  • Anonymous User - Saturday, October 25, 2003 - link

    Driver optimization in Assembly explanation is complete BS.
    Easy and nice to rearrange commands and to clean code, but NO INFO about reducing data from 24/32bit registers to 16 bit....give me a break. No IQ loss? They should change their 14" 45Hz monitors for something more up to date, and please, use LOOSELESS images at HIGH RESOLUTIONS if you dare to compare IQ....Beyond3D is definitively light years beyond you at this.

    The benchmark that's hurting NVidia more besides HL2 is of no use because of a "strange" crash. WTF? How other sites can do it? Can some one plz explain them how to install software properly?

    Fun to see how NVidia "completely dominates" when it wins by 2-3% but "it can take a punck to the chin" when is trailing by a similar number.

    TR was omitted, but they admit X2 runs like crap in FX, yet they put the scores in.

    For the last time...Gunmetal onla has 2 Vertex Shader 2.0 instructions....just to be called a DX9 test...thats all. PS are of 1.1 level.
    Aquamark just uses 4 PS 2.0...dunno about VS 2.0 if any.
    Now, Tomb Raider uses 12 PS 2.0. The game can be crappy but there are plenty used, yet that "starnge crash" wont allow people to see a future-proff scenario.



    ...should I go on?

    This is a big bunch of tree hugging hippie crap.
    [A] for sure will have a happy christmas...I wonder how much was it.
  • Anonymous User - Saturday, October 25, 2003 - link

    #85 what do you prefer? do you prefer playing 1024x768 @ 60 fps or playing 1600x1200 +FSAA 8x/6x +AA 8x @ 19 fps?
  • Anonymous User - Saturday, October 25, 2003 - link

    Is it just me or could this massive 24 page review have been fit easily into about 10 pages. I spent more time clicking to get to the next page than actually reading the review. I guess that's one way to keep your page view numbers high if you can't provide a decent analysis of the product you are reviewing.
  • Anonymous User - Saturday, October 25, 2003 - link

    LOL 83 you call other hardware sites IQ comparisons shoddy? Boy you have some mouth, go look at Anands IQ comparison in the high-end shootout. This pictures are tiny, compressed jpgs, they do NOT come in fullscreen versions, and most of them omit the ground! a part that should be required to see in any comparison. No wonder they didnt see any IQ problems, they couldnt even SEE Nvidias new filtering method because they dont even show the ground, where filtering IQ is most noticeable. Their Iq comparisons are complete BS and look like they are purposely trying to hide something from their users
  • Anonymous User - Saturday, October 25, 2003 - link

    ()_()
    ( ._.)‹^›
    ((")(")
  • Anonymous User - Saturday, October 25, 2003 - link

    I think this is hilarious,

    The day that a new graphics card comes out, one of the most REPUTABLE hardware review sites busts there ass to write an article about it and gets downplayed.

    They admit that their review is not a full review because there are other factors that they would like to invest more attention to and will release a part 2 at a later date. They go as far as to even say, "we still have more to come in the form of image quality analysis. Our findings in that arena will affect what we recommend just as much as pure speed." Which still seems unsatisfying.

    From what I've seen from EVERY other hardware review site, their IQ examples are shoddy at best (here's two images where one is f'd up, compare). A few of these posters are also much more versed in IQ technology than the rest of us (comments about trilinear filtering in a compiler setting) which is applauded and most likely the type of insight that AT will be devoting to there analysis on IQ.

    The majority of these posts, however, are nothing more than a chance for some immature limp dick computer junkie to get his rocks off by chastising one of the biggest names in hardware anonymously. I will continue to come this site and read the reviews, to learn about new technology and drool high performance electronics. And I will continue to read these comment boards, but mostly as a reminder of how pathetic some folks can be and to get a good laugh every once in awhile (still trying to get past Thomas Jefferson supporting Anal Fisting).

    -The Ways

Log in

Don't have an account? Sign up now