Original Link: http://www.anandtech.com/show/288

NVIDIA Riva TNT2

by Anand Lal Shimpi on April 27, 1999 2:32 PM EST


The law of plain reality states that when dealing with computer hardware, you will never find one product to be completely flawless. It is for that reason that the term "one-size-fits-all" does not and cannot apply to computer hardware. Just as shoes come in different sizes and styles depending on your individual needs, computer hardware does the same. Last year, the video accelerator market experienced the harsh realities of this example of common sense. Towards the end of the reign of the 3dfx Voodoo accelerator, and towards the end of the life span of the nVidia Riva 128 2D/3D accelerator, companies began stockpiling their PR efforts for the next generation of graphics chipsets to go to war. Among these chipsets were the 3dfx Voodoo2 and the nVidia Riva TNT (although they remained under code names at the time). More specific to the topic at hand, the nVidia Riva TNT was depicted as being the ultimate solution for the gamer. Even after 3dfx released their Voodoo2 nVidia continued to boast that their upcoming TNT would pack a greater punch than 3dfx could step up to handle.

As you all probably can guess, since you don’t happen to have the ultimate 2D/3D accelerator sitting in front of you, the nVidia Riva TNT never came through in terms of beating the pants off of the Voodoo2. Instead, what developed was a simple choice between the two leading competitors, 3dfx for the raw performance of their Voodoo2/Voodoo2 SLI solution, and nVidia for the superior image quality of their Riva TNT solution. Which solution was the superior one? That depends entirely on your point of view, while there are some users that prefer raw speed over image quality, there are others that prefer to enjoy a greater image quality over raw speed. Needless to say, ultimately, the year 1998 did not end up crowning any one graphics chipset manufacturer as the indisputable king of the market.

Let’s move to the present time, now one year later, can the same be said for 1999? Things are just beginning to heat up in the graphics industry. In order to remain competitive and bridge the gap between the past generation of graphics accelerators and the generation surely to come, all of the big names in the industry are releasing what AnandTech likes to call, transitional products; transitional products are essentially products that are designed to fill a void between two major releases. To put the term into context, the Intel 440LX chipset can be considered the transitional chipset between the original 440FX and the current 440BX chipset for the Pentium II processor. And speaking in more relative terms, the nVidia Riva TNT2 can be considered the transitional graphics accelerator between the original Riva TNT, and the upcoming next-generation nVidia product.

So you’ve got $130 burning a hole in your pocket, and you want to be able to play Quake 3 and Unreal Tournament without having to take coffee breaks in between frames, is the TNT2 right for you? …or is this transitional product one you’ll want to skip over?



The Specifications

There are those that will argue that the TNT2 is much more than the original TNT running at a higher clock speed, and in some respects, this is true. The TNT2’s rendering pipeline has apparently been tweaked a little by nVidia, and the TNT2 chip itself is now built upon a 0.25 micron die, a welcome change from the blazingly hot 0.35 micron wafers that the original TNTs were cut from. s320II.jpg (13511 bytes)

On the other hand, the TNT2 brings nothing dramatically new to the table, the feature set remains virtually unchanged, and the essence of the TNT remains strong in the TNT2. But have a look for yourself, as the official specs on the final revision of nVidia’s Riva TNT2 are listed below:

  • 125MHz – 150+MHz 128-bit 2D/3D core
  • 2nd Generation 128-bit TwiN Texel architecture
  • 300 Megapixels per second
  • 9 Million Triangles per second peak processing power
  • Resolution support up to 2046 x 1536
  • PCI/AGP Support – AGP 2X/4X Texturing Support
  • 16/32-bit 3D Rendering Support
  • 32-bit Z/stencil Buffer
  • 300MHz Integrated RAMDAC
  • 16/32MB SDRAM
  • 2048 x 2048 Texture Support
  • Optional NTSC/PAL Video Out
  • Optional Digital Flat Panel Output
  • Direct3D/OpenGL API Support
  • OpenGL ICD for Windows 9x, NT 3.5x, NT 4.0, and Windows 2000

Defining the TNT2

If a company does not improve on their weaknesses, their chances for success in the future are limited, right? So it makes perfect sense that nVidia should want to concentrate on their weaknesses with the TNT2, since it would make no sense to release a new product that did not offer a significant improvement over the previous flagship of the company. The first problem nVidia addressed with the TNT2 was that of clock speed, which directly effects heat production, another problem with the original TNT.

The TNT was initially supposed to ship, by the time nVidia started hinting at numbers to the media, at a core clock speed of 125MHz. If you’ve ever owned or read a review of a TNT based card, you’ll know that the 125MHz core clock never made it down to the end user, instead it was replaced by a more "comfortable" 90MHz setting. The drop from 125MHz down to 90MHz is what cost nVidia the performance race against 3dfx, and at the same time it brought nVidia more bad publicity than they could possibly have asked for. The company eventually made an announcement stating that in 6 months, a 125MHz TNT product would eventually hit the streets on a 0.25-micron silicon wafer. Now, in 1999, nVidia is finally ready to deliver on that promise.

The TNT2 starts off with an initial clock speed of 125MHz, however the technique nVidia is pushing with the release of the TNT2 is much like indirect support for overclocking. There is no clear division among the different clock speeds of TNT2 solutions as there are in the realm of the Voodoo3, rather nVidia is encouraging board manufacturers to explore whatever possibilities exist, with clock speed "suggestions" roaming around the 125MHz and 150MHz marks.



As far as the memory clock of TNT2 boards is concerned, once again, there is no set specification from nVidia, rather a suggestion that keeps the memory clock within the 140MHz  200MHz range depending on memory availability. Potentially, the TNT2 has the ability to be offered in 175/200MHz (core/memory) configurations, however realistically, the most popular and the most affordable solutions will probably be the 125MHz and 150MHz models.

Digital Flat Panel Output is an increasingly popular feature, and as you can expect, the TNT2 supports it. Although the port on the TNT2 will most likely go unused for at least another few months, the inclusion of the feature is more for marketing appeal rather than practicality. Dont worry, nVidia isnt the only one doing it, 3dfx and S3 have already hopped on this bandwagon.

2D Image Quality

One of the least frequently stressed factors in deciding on what your next graphics accelerator will be is the 2D image quality of the video card. For most users, those that run at resolutions of 1024 x 768 or less, the 2D image quality of all mainstream video cards is generally equal. However, when you take a user that is aiming to be able to use their system for games and professional applications, running at resolutions greater than 1024 x 768, and with higher refresh rates, 2D image quality does come into play.

NVIDIA tackled the problem of 2D image quality, a prominent problem with most TNT video cards, by integrating a 300MHz RAMDAC into the TNT2. The 300MHz RAMDAC, coupled with the hopefully superior design and implementation of the TNT2 in most manufacturers' cards, should make the TNT2 much more of a winner in terms of 2D image quality.

It is obvious that the 2D image quality of the TNT2 has been greatly improved over that of the TNT, however as with any discussion of 2D image quality, your mileage may vary depending on the card as well as how well your particular card was manufactured. It's unfortunate, but as long as you stick to reference design TNT2 boards, you're guaranteed 2D image quality that is at least better than the original TNT. It looks like Matrox and Number Nine will stay on top of the 2D image quality for a little while longer.

Although the TNT2 supports resolutions up to 2046 x 1536, anything above 1600 x 1200 began to grow a bit fuzzy in AnandTech's tests. Keep in mind that the TNT2 isn't a professional quality 2D accelerator, but for a chipset that will be sold on boards for around $120, the TNT2 isn't half bad. Depending on the card manufacturer and the quality of the board, a TNT2 is about on-par with that of a Voodoo3 in terms of 2D quality, however the 350MHz RAMDAC of the Voodoo3 3000/3500 does give it the edge in some cases.

The 2D performance of the TNT2 is on-par with that of 3dfx's Voodoo3 3000, but you should keep in mind that 2D performance is at a point right now where there is very little difference between two competitors of the same generation. Instead, you'll want to concentrate on the image quality of those 2D performers, something you don't always consider when you're in the market for a 3D accelerator.



3D Image Quality

Here's where the debate begins and the flames start to sizzle, the age-old image quality debate (ok, so it's not that old). The TNT2, without a doubt, provides for better image quality than any 3dfx product on the market, even when rendering in 16-bit color. This point cannot be argued, however the extent of the quality improvement of the TNT2 over the Voodoo3 can be debated.

The TNT2 supports textures in resolutions up to 2048 x 2048 (2K x 2K), this is the highest resolution any desktop 3D accelerator provides support for currently. On the reverse side of things, 3dfx only supports textures up to 256 x 256 in size.

This is what the texture looks like on a TNT2
textures-ati.jpg (100937 bytes)

This is what the texture looks like on a 3dfx accelerator
/reviews/video/voodoo3-super7/textures-v3.jpg (87401 bytes)

So is the TNT2 noticeably superior to the Voodoo3 in terms of 3D image quality? As of now, not entirely. There aren't any games currently available that truly take advantage of what the TNT2 has to offer, however both idSoftware's Quake3 Arena and GT Interactive's Unreal Tournament will make use of texture resolutions greater than 256 x 256 bytes. While you may not notice a huge difference in image quality today, the most popular games are yet to come; the discussion of 3D image quality will be continued more accurately once either of those two titles is released, then we'll be able to truly decide what the advantages/disadvantages are.

In addition to support for larger texture sizes, the TNT2 also supports 32-bit rendering, a feature that has never been present in a 3dfx accelerator. The TNT2, unlike the original TNT, can perform 32-bit rendering with much less than a 50% performance hit. The performance drop this time around is, on average, around 10 - 25% depending on the situation. In most cases, playing in 32-bit color is an extremely viable option. Keep in mind that higher resolutions will experience a more noticeable drop in performance when rendering in 32-bit color, even to the point that 1600 x 1200 is completely unplayable on a Pentium III 500 in 32-bit color, while it is playable under 16-bit color.



Driver Issues

The Voodoo3 the TNT2 was compared to, boasted final release candidate drivers, unfortunately the same cannot be said about the TNT2. NVIDIA is still tweaking their drivers, and until they are completely finished, no complete performance evaluation can be performed on the TNT2. The OpenGL ICD the TNT2 boasts is quite similar to that of the original TNT, in fact, according to the file description, it is the same file the original TNT used with its detonator drivers. So don't expect the OpenGL performance of the TNT2 to experience any 50% boosts in performance with a few driver tweaks.

cp3.gif (35057 bytes)

The Direct3D performance of the TNT2 is another story, there is much room for improvement there, and it wouldn't be surprising if NVIDIA were to release updated drivers that happened to improve performance by a noticeable factor upon the mass shipment of the TNT2. The TNT2 works perfectly fine with the detonator drivers located on NVIDIA's website, however in order to achieve the maximum performance possible, AnandTech used NVIDIA's beta drivers for the TNT2, version number 0172. Keep in mind that the performance of the TNT2 isn't set in stone, and it can only improve from this point on, so keep your eyes peeled as the benchmarks you're about to see already illustrate a pretty close competition between the TNT2 and the Voodoo3.

In terms of 3DNow! support and Super7 compatibility, AnandTech's tests found the compatibility of the latest TNT2 drivers with Super7 chipsets to be a bit on the poor side. Fortunately, there is much hope for AMD K6-2/3 owners, the rumors that NVIDIA has been working on 3DNow! enhanced drivers seem to be more well founded than you may think. There's definitely something in the works over at NVIDIA, and I wouldn't be surprised if real 3DNow! enhancements started popping up in their drivers. The condition of the drivers AnandTech tested, and the word that improved 3DNow! drivers were on the way kept the Super7 platform out of this comparison. Just as with the Voodoo3 review, Super7 users will receive a completely separate review addressing their unique needs shortly.

The stability of the 0172 drivers under OpenGL was just as you'd expect, simply because the OpenGL ICD used with the TNT2 is identical to that of the one implemented in the TNT's own detonator drivers. The Direct3D operation was a bit flaky, however it did not prevent AnandTech from completing all of the tests necessary for a thorough review.

Most card manufacturers will provide their users with an overclocking utility to "tweak" the speed of their TNT2 cards, chances are you won't need to shell out the extra cash for a higher clock speed TNT2 if you choose your card wisely. cp9.gif (6443 bytes)

Enough babble, are you ready for some numbers? Let's take a look at the test configuration



The Test

AnandTech received a pre-release version of Leadtek's WinFast 3D S320 II Riva TNT2 (16MB) card. The card was spec'd to run at 150MHz core and 170MHz memory. AnandTech's Slot-1/Socket-370 test configuration was as follows:

  • Intel Pentium III 500, Intel Pentium II 400, Intel Pentium II 266, Intel Celeron 333, Intel Celeron 266 (0KB L2) on an ABIT BX6 Revision 2.0 or an ABIT ZM6 for the Socket-370 Celeron 333 tests.
  • 64MB of Memman/Mushkin SEC Original SDRAM was used in each test system
  • Western Digital 5.1GB Ultra ATA/33 HDD
  • Microsoft Windows 98

The benchmark software used was as follows:

  • id Software's Quake 2 Version 3.20 using demo1.dm2 and 3Finger's crusher.dm2
  • Monolith's Shogo using 3Finger's RevDemo
  • Interplay's Descent3 Demo2 using AnandTech's Descent3 Torture Demo
  • Ziff Davis' Winbench 99 at 1600 x 1200 x 32-bit color for 2D performance tests

Each benchmark was run a total of three times and the average frame rates taken. Vsync was disabled.



Quake 2 Performance - demo1.dm2

Q2D1-P3/500



Q2D1-P2/400



Q2D1 - P2/266



Q2D1 - C333A

 



Q2D1 - C266



CPU Scaling Performance



OpenGL Performance - Quake2 crusher.dm2

Q2C - P3/500



Q2C - P2/400



Q2C - P2/266



Q2C - C333A



Q2C - C266



CPU Scaling Performance



Quake 2 Performance Conclusions

Under Quake 2, the more mature drivers of the Voodoo2/Voodoo3 keep nVidia out of the top ranks here.  Keep in mind that the TNT2's drivers still have some growing to do before they can be considered final release candidates, whereas the Voodoo3 drivers are as close to final as they're going to get for the time being.  On faster CPUs, such as the Pentium II 400 and the Pentium III 500, the TNT2 is not all that much slower than the Voodoo3, and its 32-bit rendering performance is great enough for most users to run under 32-bit rendering without complaining too much.  Unfortunately, just as the original TNT was incredibly CPU dependent, the TNT2's competitive performance, particularly at higher resolutions and when rendering in 32-bit color, begins to drop on slower CPUs. 

The difference between the 125MHz and the 150MHz (core) TNT2's is great enough to justify a user opting for the 150MHz or higher clocked parts, however on slower CPUs, the limiting factor ends up being the CPU, making the 150MHz TNT2 no different than its slower 125MHz counterpart.

Needless to say, under Quake 2, the TNT2 doesn't "smoke" the competition, nor does it fail miserably.  Does anyone else see the same image quality vs performance argument emerging once again?



Direct3D Performance - Shogo RevShogo

Shogo - P3/500



Shogo - P2/400



Shogo - P2/266



Shogo - C333A



Shogo - C266



CPU Scaling Performance



Shogo Performance Conclusions

Just like the original TNT, the TNT2 truly begins to shine under Direct3D.  As you can tell by the benchmarks, the 150MHz TNT2 went up against the 166MHz Voodoo3 3000 and still came out either even or on top at the higher resolutions.  Keeping in mind that the TNT2's drivers are still quite beta, the TNT2 is definitely a strong Direct3D performer.  The performance lead over the Voodoo3 extends to the point where even the 125MHz TNT2 manages to outdistance the 143MHz Voodoo3 2000.  Unfortunately, the same trend does not continue on with the slower CPUs, the Voodoo3 dominated the Pentium II 266 scores, and the 3dfx name reigned completely on the Celeron platform, especially the cacheless Celeron 266.  In spite of this, the TNT2 will prove to be the faster overall solution for users of the higher clock speed Celerons, as anything above the performance of the Pentium II 400 seems to begin to noticeably tilt the balance of power in favor of NVIDIA. 

The CPU scaling performance graphs show how well the TNT2 scales with processor performance, it looks like the TNT2 won't be maxing out its performance anytime soon. 



Direct3D Performance - Descent3 AnandTech Demo

AnandTech needed another Direct3D demo, using the latest Descent3 demo AnandTech put together a real world torture test focusing on gameplay during which the frame rate drops to an extremely low point as well as peaks at the maximum possible output by the video card.  The demo can be downloaded here.  To run the demo, download the Descent3 Demo2, select your rendering device, set the detail levels to "Highest" and be sure to disable the cockpit of the ship.  Then simply use the View Demo option in the main menu once you're in the game and select the at.dem file and run the demo.  After it is complete, a low, high, and average frame rate will be outputted to the screen.

D3 - P3/500



D3 - P2/400



D3 - P2/266



D3 - C333A



D3 - C266



Descent 3 Performance Conclusion

The Descent 3 demo is the perfect example of the benefits of Glide in a game. While the 150MHz TNT2 managed to defeat 3dfx's 166MHz Voodoo3 in most tests, the margin of defeat decreased considerably when 3dfx's Glide API was used instead of Direct3D as the default rendering device. For owners of slower CPUs, the Voodoo3's Glide support will come in handy as it does give 3dfx the edge over NVIDIA, however if a game doesn't support Glide, then you may be out of luck.

The TNT2's ability to handle larger textures (using the currently implemented AGP2X support) with style and speed give it the added edge over 3dfx in Descent 3, as the TNT2 dominated the 1024 x 768 resolution, especially with the Pentium III 500. Users with slower CPUs are better off with the Voodoo3, however if you're planning on upgrading, the performance of the TNT2 can only go up from the point its at now, making the outlook for NVIDIA's latest, pretty promising.

Final Words

You can't really provide a final decision on a product whose drivers have yet to be finalized, and unfortunately, the drivers that most TNT2 board manufacturers will be shipping in the next week or two won't be the same high-performing drivers AnandTech used. It will take an official release from NVIDIA to spark the use of those drivers, however it may be a little while longer before that happens. When it does, you can expect the performance of the TNT2 to improve, even if it's just a little, there is still room for improvement with the already outstanding Direct3D performance of the TNT2.

Is the TNT2 the choice for you? If you happen to have a slower CPU, anything slower than a Pentium II 350 or a Celeron 366, the Voodoo3 will probably offer you greater performance for a similar price. However, a couple months down the road when you want to play a game of Quake 3, don't complain about the quality of the textures. The Voodoo3 and TNT2 both perform at a level where there is not a huge difference of performance between the two, although in some cases it is definitely noticeable. The best overall solution out of the two seems to be the TNT2, whose combination of superior image quality and above average performance do make it a powerful successor to the original TNT. Owners of first generation Pentium II's (233/266) will probably want to stick to 3dfx in this case, as the Voodoo3 is a much better choice for slower CPUs, in spite of the difference in image quality.

Another factor that must be taken into consideration is that the board AnandTech tested was only a 16MB TNT2 board, so the overall performance of the TNT2, especially at higher resolutions and color depths, should be at least a little greater than the 16MB board AnandTech previewed here. If you take that into consideration, the gap between the Voodoo3 3000 and the TNT2 clocked at 150MHz borders on non-existant.

As far as image quality is concerned, there is no real world measurement of the true benefits of the TNT2's capabilities from a quality perspective, however upon the release of idSoftware's Quake 3 Arena (at least the test), we'll be able to quantify exactly how big of a difference there is between a Voodoo3 and a TNT2 in image quality. Until then, search the web for screen shots, and decide for yourself.

Super7 users will want to wait until at least the first wave of drivers have been released from NVIDIA, as 3dfx still holds the title for best 3DNow! driver implementation. Word has it that NVIDIA is working on a killer 3DNow! implementation of their own, whether or not they release it in time to effect the buying decisions of many 3dfx entranced Super7 users is another question.

There is one factor this review did not take into account, the so called "Ultra" TNT2, or the 166MHz+ TNT2 product. AnandTech's TNT2 sample would not make it past 160MHz core, so the potential of the 166MHz+ (specifically, the 175MHz) TNT2 processors to overtake the market and become the ultimate gaming force has yet to be proven. While manufacturers have already announced support for "Ultra" TNT2 products, until AnandTech sees retail boxes shipping, the "Ultra" TNT2 will be discounted as much as the elusive Voodoo3 3500 has.

If NVIDIA does come through with the "Ultra" TNT2 in great enough quantities you can, for one thing, expect 3dfx to retaliate with rushed production of the 3500, as well as expect to pay an added premium for the extra performance. If the "Ultra" TNT2 does become a reality within the next month, it might just be that NVIDIA goes down in history as one of the few companies to break the law of reality.

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