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- Date:
- Thursday , March 13, 2003
- Author:
- Sean Pelletier
- Editor:
- Kyle Bennett
- Google +1
GeForceFX 5200 & 5600
Apples to apples performance benchmarking with the new GFFX 5200 and 5600. We also show you how NVIDIA is doing things differently and if they are really selling a "cinematic" experience or not.
Figuring Out How to Test
Per NVIDIA’s recommendation, all benchmarks for this review were initially run with the “Aggressive” image quality slider selection within the drivers. Once some of the data had been collected from the benchmarks, we began sampling the image quality for each card for comparative evaluation. One glance at the screenshots revealed that something was amiss with the NVIDIA cards IQ (Image Quality).
We use ATI's "Quality" settings in their driver for our testing. It delivers a very good image overall and ATI cards such as the 9500 and 9700 series perform well while delivering this. At "Quality" settings the ATI graphics cards use Trilinear Filtering to enhance image quality which is widely considered the norm as it produces a very good mip-map blend as objects are shown farther away from you in a game. This is the same standard that we think the NVIDIA card should be held to for our testing needs.
However, when running in the recommended setting of "Aggressive" mode on the NVIDIA graphics cards we found they do not use Trilinear Filtering. Instead, the card utilizes NVIDIA's own per-pixel adaptive algorithm whose resulting image quality is better than Bilinear Filtering, but certainly not up to Trilinear Filtering. This Aggressive setting positioned the NVIDIA GFFX cards at a distinct frame rate performance advantage, compared even to their own "Balanced" mode that is lacking true Trilinear Filtering, due to the fact that they are not saddled with the workload of Trilinear Filtering. As additional testing revealed, the average frame rate performance of the NVIDIA graphics cards dropped significantly once Trilinear Filtering was forced by application settings.
We soon realized that NVIDIA's Aggressive settings did not reflect the IQ we have come to expect and it surely did not equate to fair "apples-to-apples" benchmarks. So we set out to figure what exactly was going to represent a fair comparison between our ATI and NVIDIA cards while preserving the IQ we all find so important, or better yet that quality that gives us a "cinematic experience".
In an effort to bring everyone up to speed, we will outline the various quality settings within the NVIDIA driver control panel.
Looking at the "Quality and Performance" tab within the drivers, we find that the user has three choices for the Performance setting. Here they have the choice between "Application", "Balanced", and "Aggressive". Initially, we will look at how each setting differs from the other in terms of image quality. To do this, a handful of games were selected and run. By saving the game at a position which would suit this comparison best, we could use the spawn-point to ensure that each screenshot would be identical.
In an effort to make this issue a bit easier to identify, we ran Q3 with Trilinear Filtering enabled at 1024x768 with the mip-map colorization enabled. Essentially, a mip-map is a pre-filled texture pattern which represents a portion of the entire image. When looking at the screen, you will see several different mip-maps represented by a different color. Every transition from one color to the next will represent a transition from one mip-map to another. Using these colorized mip-maps, Trilinear Filtering should blend each color evenly into the other without any clear lines of distinction. Should any strange filtering be going on, this approach will ensure that we will easily see the visual discrepancies. A sequence of screenshots was taken using the console command with and without 8x Anisotropic Filtering for each of the three quality modes.
Looking at the first image above which uses the “Aggressive” setting, we find the scene to have a great deal of separation between each mip-map, meaning that the way the each mip-map blends into each other is done so without a subtle transition like you would expect to find in quality filtering. The lack of blending in this case illustrates the fact that full Trilinear Filtering is not present. Once 8X AF is enabled, we find a rather strange situation regarding the orientation of the mip-maps. Whereas the mip-maps where arranged in a convex pattern when no AA or AF was present, the mip-maps are now spread in a concave pattern across the screen. We have asked NVIDIA for an explanation of why this is happening and are awaiting an "official" answer. Certainly this shows that NVIDIA is doing their own brand of Anisotropic Filtering. Regardless, the color bands are still very isolated from one another indicating the presence of a lower level of filtering.
Moving to the “Balanced” screenshot in the middle, we see that the situation has improved. Here, we are beginning to see the drastic line of distinction between each mip-map gradually fade. This indicates that a higher level of filtering is present, though the degree of that filtering level is questionable. Though some blending is taking place, the colors remain very concentrated and fail to mix enough to avoid showing the same line of distinction. Unfortunately, things remain roughly the same once we enable 8X AF. Although NVIDIA claims that Balanced mode will use Trilinear Filtering when AF is present, we can clearly see that "full" Trilinear Filtering is not present. Instead, we are faced with NVIDIA's own adaptive algorithm which fails to provide the desired level of image quality.
Moving to “Application” mode, we are forcing the application itself to dictate the level of quality which will be used. Through using this mode and selecting Trilinear Filtering within the game, we are assured that this level of image quality will be used. Viewing the first image above, we finally see a situation where Trilinear Filtering is present in its full capacity. With this setting selected, the mip-map colors effectively meld with one another to create a smooth transition throughout the scene. Once 8X AF is selected, we are again presented with the level of image quality we have been searching for. Here, each color seamlessly blends into the next creating a very clean image. This is the setting that illustrates that "application" mode is the only true way to compare the NVIDIA cards with the ATI cards running Trilinear Filtering.
As you can see above we have now found a level of image quality that we can say is "fair" for benchmarking. You can see the GeForce FX 5600 Ultra's image is now on par with the Radeon 9500 Pro by referencing the above mip-map paths and transitions. True Trilinear Filtering is enabled within the game along with maximum image quality settings. The 9500 Pro is running in "Quality" mode whereas the GeForce FX 5600 Ultra is utilizing "Application". Now that we know that NVIDIA is handling filtering in ways that we are used to, be it wrong or right, we can adjust and make sure that we have comparable frame rate data.
In an effort to pull this together a bit more, we have spliced the screenshots together to form one image to contrast the filtering used. You can click on this image to see the full 1024x768 version which highlights this issue even further. In each case, the image was run using each of the three quality modes with maximum image quality settings and Trilinear Filtering selected within the game. For this series of screenshots, no level of FSAA or AF was enabled.
Quake 3
1MB dl
Referencing the image above, it quickly becomes apparent how dramatic the image quality is between each setting. For the sake of simplicity, we will focus our attention on one specific point within each section. Viewing the first section which represents image quality using the "Aggressive" mode, we clearly see a sharp definition between the green and red mip-map levels around the number "1". This will act as our point of reference for this quality mode. The middle portion of this image is a reflection of the image quality when running in "Balanced" mode. Looking at the reference point number "2", we see a slightly more blended line of demarcation between the red and green mip-maps. Lastly, the final scene illustrates the quality of "Application" mode. Surrounding reference point number "3", we see the desired saturation effects of Trilinear Filtering. At this setting, it is almost impossible to discern a line of separation between the green and red mip-maps.
Technique or Quality?
Before you leave this page, please keep in mind that NVIDIA is in no way bound to use Trilinear Filtering. There is no doubt in my mind that we will see better and different ways of doing these things in the future and this is possibly a beginning of that. But we are in the position to make sure that when we deliver comparative data to you, that we do it in the fairest possible manner. So for this article, we are going to show you how the GFFX family plays out using several different IQ settings and then we will look at some images. You can then make up your own mind on whether or not NVIDIA's lack of Trilinear Filtering in their Aggressive and Balanced modes really makes a difference that you care about.