NVIDIA's Back with NV35 - GeForceFX 5900 Ultra
by Anand Lal Shimpi on May 12, 2003 8:53 AM EST- Posted in
- GPUs
Stage 1: "The Front End"
The first stage of the graphics pipeline, as we mentioned before, is the initial stage where the application (in most cases a game) communicates with the API/driver and in turn talks to the GPU.
Instructions from the game being run are sent to the API, telling it to tell the hardware what the game wants to do. The API then interfaces with the graphics driver and passes on the API code. There is a real-time compiler in the graphics driver that takes the API code and essentially maps it to instructions that the particular GPU can understand, this is the first place where ATI and NVIDIA are divided. While both ATI and NVIDIA have the same approach, ATI's real-time compiler obviously generates instructions that only their GPUs can understand, while NVIDIA's compiler is tailored to NVIDIA GPUs only; makes sense, no?
What is contained in these instructions that are sent to the GPU? For all pre-DX8 code ("non-programmable"), vertices, indeces, commands that instruct the GPU where to go fetch vertices/indeces from or states (e.g. z-buffer enable/disable, texture filtering mode = trilinear, etc…) are the types of instructions you can expect to see in this stage. As we mentioned in our overview of the graphics pipeline, this stage mainly tells all of the other stages what to do, which is exactly what's happening here.
For DX8/DX9 code things are a bit different, as there are actual vertex/pixel programs that are sent to the driver and then mapped to GPU machine code. The difference between this approach and pre-DX8 code is that pre-DX8 code would trigger a series of events that would happen in the pipeline (e.g. lookup this texture, apply it to these pixels, repeat, etc…) whereas DX8/DX9 code offers much more flexibility for the programmer. Now the developer can tell the vertex shader FPUs to perform any task they would like, even to the point of coding non-graphics programs to run on the GPU. When DX8/DX9 code is sent to the GPU, the processor acts much more like a conventional CPU; a GPU running DX8/DX9 code is a lot like a CPU running any application you would on your computer.
Both ATI and NVIDIA are very stringent on details involving these front end stages of their pipelines, but as you can guess it is quite difficult to compare the two here. The efficiency and performance of the driver's real-time compiler is extremely important to how well these first set of operations perform.
The one thing you have to keep fresh in your mind about the graphics pipeline is that many parts of the pipeline are extremely parallel in nature, and thus optimizing the amount of parallelism in the code the compiler generates is key to extracting the full performance potential out of any GPU. The compiler dictates what registers data will be stored in, it handles any and all bundling of instructions and as we just mentioned, attempts to extract as much Instruction Level Parallelism (ILP) from the code as possible.
If you've ever wondered how newer drivers can increase performance, improvements in the driver's real-time compiler are often the reason for performance gains. The beauty of having a real-time compiler in the driver is that we don't have to wait for applications to take advantage of the hardware (for the most part) for us to get a performance boost from a brand new architecture. This is in sharp contrast to how things work in the CPU world where it takes a number of revisions before an application is recompiled with optimizations for a brand new CPU architecture. The graphics world will continue to use real-time compilers until the shader programs grow to be long enough that compiling at runtime is impossible, but it seems like that's going to be some time from now.
Along these lines, a good deal of the performance improvement with the new Detonator FX drivers is due to compiler optimizations for the new NV3x architecture. The next question is who makes a better compiler - ATI or NVIDIA? Compiler research and development is definitely new stomping grounds for both companies, but one thing is for sure, the more experience any driver team has with a new architecture, the better their compiler will be. In the case of ATI, they have been working on the R3xx compiler on real hardware since July of last year, whereas NVIDIA hasn't had nearly as much time with NV3x. The other factor aside from raw experience, is which driver team is more talented. We'll leave that one alone as we're not here to review resumes...
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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
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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...