The Chip

R420 is a very power GPU in tight little package. ATI opted not to go with full DirectX 9.0 Shader Model 3.0 support in their latest GPU, but that doesn't mean that this chip doesn't pack a punch. Here's a breakdown of what's on the top of the line playing field now.

  NV38 NV40 R360 R420
Transistors
130M
222M
110M
160M
Core clock
475MHz
400MHz
412MHz
500MHz
Mem clock
950MHz
1.1GHz
900MHz
1.12GHz
Memory Bus
256bit
256bit
256bit
256bit
Vertex Pipelines
~4
6
4
6
Pixel Pipelines
4x2
16x1
8x1
16x1
Shader Model
2.0+
3.0
2.0
2.0+
Fab Process
130nm
130nm
150nm
130nm

  GeForce 6800 GT GeForce 6800 Ultra GeForce 6850 Ultra Radeon X800 Pro Radeon X800 XT PE
Price
$399
$499
$499+
$399
$499

The first thing we see is that R420 has the highest clock speed (giving it the highest peak fillrate), and it just edges out NV40 for memory speed. Of course, these theoretical numbers don't really translate directly into performance. In order to understand where performance comes from, we'll need to take a much closer look at the architecture.

Before we get in over our heads on this, it is important to differentiate the hardware itself from how the hardware looks in terms of a graphics API. Both NVIDIA and ATI, in presenting their hardware to us, have relied heavily on using the constructs of DirectX 9 to explain what's going on at different stages in the pipeline. This is useful in that we can understand how the hardware looks to the software, but there are some caveats. We will be keeping this in mind as we look over the new offerings from ATI and NVIDIA.

Index The R420 Vertex Pipeline
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  • rms - Tuesday, May 4, 2004 - link

    "the near-to-be-released goodlooking PS 3.0 Far Cry update "

    When is that patch scheduled for? I recall seeing some rumour it was due in September...

    rms
  • Fr0zeN - Tuesday, May 4, 2004 - link

    Yeah I agree, the GT looks like it's gonna give the x800P a run for its money. On a side note, the differences between P and XT versions seem to be greater than r9800's, hmm.

    In the end it's the most overclockable $200 card that'll end up in my comp. There's no way I'm paying $500 for something that I can compensate for by turning the rez down to 10x7... Raw benchmarks mean nothing if it doesn't oc well!
  • Doop - Tuesday, May 4, 2004 - link

    The cards seem very close, I tend to favor nVidia now since they have superior multi monitor and professional 3D drivers and I regret buying my Fire GL X1.

    It's strange ATi didn't announce a 16 pipeline card orginally, it will be interesting to see in a month or two who actually ends up delivering cards.

    I mean if they're being made in significant quantities they'll be at your local store with a reduced 'street' price but if it's just a paper launch they'll just be at Alienware, Dell (with a new PC only) or $500 if you can find one.
  • jensend - Tuesday, May 4, 2004 - link

    #17, the Serious Engine has nothing to do with the Q3 engine; Nvidia's superior OpenGL performance is not dependent on any handful of engines' particular quirks.

    Zobar is right; contra Jibbo, the increased flexibility of PS3 means that for many 2.0 shader programs a PS3 version can achieve equivalent results with a lesser performance hit.

    As far as power goes, I'm surprised NV made such a big deal out of PSU requirements, as its new cards (except the 6800U Extremely Short Production Run Edition/6850U/Whatever they end up calling that part) compare favorably wattage-wise to the 5950U and don't pull all that much more power than the 9800XT. Both companies have made a big performance per watt leap, and it'll be interesting to see how the mid-range and value cards compare in this respect.
  • blitz - Tuesday, May 4, 2004 - link

    "Of course, we will have to wait and see what happens in that area, but depending on what the test results for our 6850 Ultra end up looking like, we may end up recommending that NVIDIA push their prices down slightly (or shift around a few specs) in order to keep the market balanced."

    It sounds as if you would be giving nvidia advice on their pricing strategy, somehow I don't think they would listen nor be influenced by your opinion. It could be better phrased that you would advise consumers to wait for prices to drop or look elsewhere for better price\performance ratio.
  • Cygni - Tuesday, May 4, 2004 - link

    Hmmmm, interesting. I really dont see where anyone can draw the conclusion that the x800 Pro is CLEARLY the winner. The 6800 GT and x800 Pro traded game wins back and forth. There doesnt seem to be any clear cut winner to me. Wolf, JediA, X2, F1C, and AQ3 all went clearly to the GT... this isnt open and shut. Alot of the other tests were split depending on resolution/AA. On the other hand, I dont think you can say that the GT is clearly better than the x800 Pro either.

    Personally, I will buy whichever one hits a reasonable price point first. $150-200. Both seem to be pretty equal, and to me, price matters far more.
  • kherman - Tuesday, May 4, 2004 - link

    BRING ON DOOM 3!!!!!!

    We all know inside that this is what ID was waiting for!
  • Diesel - Tuesday, May 4, 2004 - link

    ------------------
    I think it is strange that the tested X800XT is clocked at 520 Mhz, while the 6800U, that is manufactured by the same taiwanese company and also has 16 pipelines, is set at 400 Mhz.
    ------------------

    This could be because NV40 has 222M transistors vs. R420 at 160M transistors. I think the amount of power required and heat generated is proportional to transistor count and clock speed.
  • edub82 - Tuesday, May 4, 2004 - link

    I know this is an ATI article but that 6800 GT is looking very attractive. It beats the x800Pro on a fairly regular basis is a single slot and molex connector card and is starting at 400 and hopefully will go down a few dollars ;) in 6 months when i want to upgrade.
  • Slaanesh - Tuesday, May 4, 2004 - link

    "Clearly a developer can have much nicer quality and exotic effects if he/she exploits these, but how many gamers will have a PS3.0 card that will run these extremely complex shaders at high resolutions and AA/AF without crawling to single-digit fps? It's my guess that it will be *at least* a year until games show serious quality differentiation between PS2.0 and PS3.0. But I have been wrong in the past..."
    --------

    I dunnow.. When Morrowind got released, only he few GF3 cards on the market were able to show the cool pixel shader water effects and they did it well; at that time I was really pissed I went for the cheaper Geforce2 Ultra although it had some better benchmarks at a much lower price. I don't think I want make that mistake again and pay the same amount of money for a card that doesnt support the latest technology..

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