NVIDIA's Back with NV35 - GeForceFX 5900 Ultra
by Anand Lal Shimpi on May 12, 2003 8:53 AM EST- Posted in
- GPUs
The Graphics "Pipeline" (continued)
The incredibly long graphics pipeline can be summarized into six general stages, which we'll further dive into later in this article.
1) Instruction Fetch/Decode, DMA, etc…
This stage is one that receives instructions and commands from the driver and decodes them into operations for all other parts of the graphics pipeline to perform. This is the stage that tells all of the other countless stages what to do.
2) Vertex Processing
Now that the GPU knows what data it needs to begin processing and what it needs to actually do to this set of data, it starts working. The data sent to the GPU is sent in the form of the vertices of the polygons that will eventually be displayed on your screen. The first actual execution stage in the graphics pipeline is what has been referred to as T&L for the longest time. This is the transformation of the vertex data that was just sent to the GPU into a 3D scene. The transformation stage requires a lot of highly repetitive floating-point matrix math. Next comes the actual lighting calculations for each of these vertices. In a programmable GPU these initial vertex processing stages are very flexible in that short vertex shader programs can be written to control a number of the characteristics of the vertices to change the shape, look or behavior of a model among other things (e.g. matrix palette skinning, realistic fur, etc..). This stage is actually a pipeline of its own, split into a number of smaller stages.
3) Triangle Setup
After we have beautifully transformed and lit vertices it's time to actually generate some pixels so they can be displayed on your screen. But before that there's a bit of house keeping to be done. There are the culling and clipping stages that basically remove all the vertices that extend beyond the bounds of the scene. Then we have some of the nifty visibility calculations that go on in most of today's GPUs to help throw out vertices that won't be visible to the user. This is where technologies such as HyperZ and NVIDIA's Visibility Subsystem come into play to throw out data before we actually start rendering pixels and waste fill-rate and memory bandwidth. Here the vertices are transformed into primitives (e.g. triangles).
4) Rasterization
Now that we've had our spring cleaning it's time to generate some pixels. The triangles we just generated are now converted into pixels in the viewport space which is the 2D space of your monitor; remember that although this is 3D rendering, you're still looking at a flat (2D) monitor. The z-buffer data (how far away/deep the pixels are in reference to the viewer) is calculated and stored as well in order to turn this otherwise 2D image into a 3D world.
5) Shading & Texturing
Although shading and texturing are two separate stages, they are tightly coupled and occur in parallel. These stages are also pipelines of their own, but as we just mentioned they occur in parallel. Texture coordinates are calculated which will be used to map textures onto these polygons that have been created using the vertex data. The textures are then loaded and then we have the pixel shading stage where today's programmable GPUs can allow small programs to run and create neat looking effects on the pixels (e.g. shadow mapping, z-correct bump mapping, etc…). There is a bypass/feedback network that exists between these pipelines so that data from one pipe may be fed back into a different pipe in order to perform additional rendering passes, shading calculations, etc…
6) Raster Operations
This stage is where all pixel level operations occur, such as z/color/stencil rendering, as well as anti-aliasing and texture filtering.
7) DRAM accesses/Put it on the Screen
At the end of the pipeline we have all final DRAM accesses that must take place so we can write these pixels we've worked so hard at generating to memory before sending the data off to the RAMDACs or TMDS transmitter(s) for display on your monitor.
Now that you've got a general idea of the overall 3D pipeline, let's further dive into each stage and see how the NV35 (GeForceFX 5900 Ultra) and the R350 (Radeon 9800 Pro) are similar and different, architecturally.
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Anonymous User - Thursday, October 16, 2003 - link
After reading this article, how can I determine which GeForceFX 5600 card has the NV30 core or the NV35 core. I'm currently interested in purchasing one, but on any of the retail boxes or manuals from the manufacturer's web site say nothing about the type of core used. Did NVidia corrected themselves using the NV35 core before releasing their 5600 cards to the market? Or are there 5600's NV30 cards on the retail shelves too. Help is appreciated. Thanks.JamesVon - Thursday, December 27, 2018 - link
Have you tried to play any Fortnite in GeForceFX 5600? Actually you can get free v-bucks or free fortnite leaked skins here if you interested <a href="https://newfortnite.com/">https://newfortn...Anonymous User - Saturday, September 6, 2003 - link
You should be ashamed. The linking of words to completely unrelated MARKETING ADS is absolutely ridiculous...as if you don’t have ENOUGH ads already.-J
Shagga - Saturday, August 9, 2003 - link
I certainly found the article informative. I read the article with a view to making a decision on which card to purchase over the next week or so and to be honest the article said enough to convince me to sit tight. I also felt there is more to come from both ATI and nVidia and the results which are presented are perhaps not entirely complete. This is pointed out by Anand and at $499 I need to be making the right choice, however, Anand did succeed in convincing me to wait a tad longer.Good article I thought.
Anonymous User - Friday, August 1, 2003 - link
Please stop using Flash graphics!JamesVon - Thursday, December 27, 2018 - link
What is the problem with Flash Graphics? Have you tried using Steam Platform? You can get free steam keys here https://steamity.com if you want to download free steam gamesPete - Tuesday, July 22, 2003 - link
It's only fair that I praise the article, as well. As I said above, in the initial article comment thread, I congratulated Anand on what I thought was a well-written article. I appreciate his lengthy graphics pipeline summary, his extensive image quality investigation, and his usual even-handed commentary (though I had problems with the latter two).Pete - Tuesday, July 22, 2003 - link
I think this is a great article with a few significant flaws in its benchmarking.Firstly, the Doom 3 numbers. Anand acknowledged that he could not get the 9800P 256MB to run the tech demo properly, yet he includes the numbers anyway. This strikes me as not only incorrect but irresponsible. People will see 9800P 256MB numbers and note that its extra memory makes no difference over its 128MB sibling, yet only if they read the article carefully would they know that the driver Anand used limits the 9800P 256MB to only 128MB, essentially crippling the card.
Also, note the difference between Medium Quality and High Quality modes in Doom 3 is only anisotropic filtering (AF), which is enabled in HQ mode. Note that forcing AF in the video card's drivers, rather than via the application, will result in higher performance and potentially lower image quality! This was shown to be the case both in a TechReport article on 3DM03 ("3DMurk"), in forum discussions at B3D, and in an editorial at THG. Hopefully this will be explored fully once a Doom3 demo is released to the public, and we have more open benchmarking of this anticipated game.
Secondly, Anand's initial Quake 3 5900U numbers seemed way off compared to other sites that tested the same card in similar systems at the same settings. At 1600x1200 with 4xAA 8xAF, Anand was scoring over 200fps, well higher than any other review. And yet, after weeks of protest in the forum thread on this article, all that happened was the benchmark results for 12x10 and 16x12 were removed. The text, which notes:
"The GeForceFX 5900 Ultra does extremely well in Quake III Arena, to the point where it is CPU/platform bound at 1600x1200 with 4X AA/8X Anisotropic filtering enabled."
was left unchanged, even though it was based on what many assumed were erroneous benchmark data. I can only conclude that the data were indeed erroneous, as they have been removed from the article. Sadly, the accompanying text has not been edited to reflect that.
Thirdly, the article initially tested Splinter Cell with AA, though the game does not perform correctly with it. The problem was that NVIDIA's drivers automatically disable AA if it's selected, yielding non-AA scores for what an unsupsecting reviewer believes is an AA mode. ATi's driver allow AA, warts and all, and thus produce appropriately dimished benchmark numbers, along with corresponding AA errors. The first step at correcting this mistake was to remove all Splinter Cell graphs and place a blurb in the driver section of the review blaming ATi for not disabling AA. Apparently a second step has been taking, expunging Splinter Cell from the article text altogether. Strangely, Splinter Cell is still listed in the article's drop-down menu as p. 25; clicking will bring you to the one last Quake 3 graph with the incorrect analysis, noted above.
Finally, a note on the conclusion:
"What stood out the most about NVIDIA was how some of their best people could look us in the eye and say "we made a mistake" (in reference to NV30)."
What stands out most to me is that NVIDIA still can't look people in the eye and say they made a mistake by cheating in 3DMark03. Recent articles have shown NVIDIA to be making questionable optimizations (that may be considered cheats in the context of a benchmark) in many games and benchmarks, yet I see only a handful of sites attempt to investigate these issues. ExtremeTech and B3D noted the 3DMark03 "optimizations." Digit-Life has noted CodeCreatures and UT2K3 benchmark "optimizations," and Beyond3D and AMDMB have presented pictorial evidence of what appears to be the reason for the benchmark gains. NVIDIA appears to currently foster a culture of cutting corners without the customer's (and, hopefully, reviewer's) knowledge, and they appear reticent to admit it at all.
I realize this post comes off as harsh against both Anand and NVIDIA. In the initial comment thread on this article, I was gentler in my (IMO, constructive) criticism. As the thread wore on for weeks without a single change in the multiple errors perceived in the original article, I gradually became more curt in my requests for corrections. Anand elicits possibly the greatest benefit of the doubt of any online hardware reviewer I know, as I've read his site and enjoyed the mature and thoughtful personality he imbued it with for years. I'm sorry to say his response--rather, his lack of response, as it was only Evan and Kristopher, not Anand, that replied to the original article thread--was wholly unsatisfactory, and the much belated editing of the article into what you read today was unsatisfactory as well. I would have much preferred Anand(tech) left the original article intact and appended a cautionary note or corrected benchmarks and commentary, rather than simply cutting out some of the questionable figures and text.
Consider this post a summation of the criticism posted in the original article thread. I thought they would be useful to put this article in context, and I hope they are taken as constructive, not destructive, criticism. The 5900 is no doubt a superior card to its predecessor. I also believe this article, in its current form, presents an incomplete picture of both the 5900U and its direct competition, ATi's 9800P 256MB. Hopefully the long chain of revelations and commentary sparked by and after this article will result not in hard feelings, but more educated, thorough, and informative reviews.
I look forward to Anandtech's next review, which I believe has been too long in coming. :)
ritaeora - Tuesday, December 11, 2018 - link
I like your review about the GeForce.http://www.linkedin.com/company/free-instagram-fol...
kyrac - Monday, December 24, 2018 - link
I am a user of Nvidia and i have a great experience using it.https://www.linkedin.com/company/virtual-assistant...