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The Radeon X800XL and GeForce 6800GT Compared

PCI Express x16 graphics cards
Chipset Radeon X800XL 256 MB, 256 bit, GeForce 6800GT 256 MB, 256 bit

To get a better picture of what these cards have to offer, we've decided to re-evaluate our suite of benchmarks. For one, we decided to update our image test quality comparisons. We use a new scene for Call of Duty and SW: Knights of the Old Republic that will best show how good (or bad) each card deal with AA and AF. That's when we noticed something is not quite right with our Call of Duty scores. We've also re-ran our Battlefield 2 benchmark for the GeForce 6800GTs because the results was, in effect, all over the place.

Call of Duty problems

When we ran FRAPS with the Dawnville demo included in the 1.5 patch, we noticed a very large discrepancy between the results from the timedemo command and what we're getting from FRAPS. Further testing revealed even the on screen fps counter from both reports different frame rates. This happens on both ATI and NVIDIA cards, so we suspect either the in game tool or FRAPS is at fault and reporting inflated scores. We ran every timedemo we have (or can get our hands on). the results are still to far apart. To eliminate FRAPS, we ran it with several games that also feature in-game benchmarking tools, like Splinter Cell, Battlefield 2, Doom 3 and Dungeon Siege. In these games, FRAPS results are either the same or very close, at the very least within 1 fps of each other. With this evidence, we're pretty sure that the in game benchmarking tool in Call of Duty is the one providing the erroneous results. We feel pretty bad about this, since we should've caught this one earlier. This does invalidate our past Call of Duty benchmark numbers, since benchmark results between the timedemo and FRAPS is very different by a significant amount. From now on, we will use FRAPS instead of the in game tool to benchmark Call of Duty.

Battlefield 2

We've re ran and made corrections to our benchmark results for this game in our GeForce 6800GT round up, which you can check here. The cause of the problem is bots - Battlefield is pretty system dependent - if there's too few bots, you'll more likely to have higher frame rates. Thus, fluctuating scores. Now that We've discovered and fixed the problem, performance across the board is more consistent. However, this does not change our conclusion - we can see that performance is relatively the same between all boards.

Showing artifacts in motion and static images

We once said that there are several reasons people buy faster graphics cards: to get higher frame rates, to play at higher resolutions and to play with AA and AF enabled, with full or maximum details. Of course, gamers who like to play with AA and AF will most likely be more concerned with image quality than most people. Higher frame rates are easily to show, but image quality differences are not, because image quality is generally, very subjective. There are some guidelines, but in general image quality comparisons can be very tricky to do. Games may have different rendering paths for each vendor (ATI and NVIDIA) or even implement different levels of detail. Cards from both have different approaches to 3D rendering. Optimizations (valid and not) only complicates the matter further.

The most obvious way of course is to show screenshots taken in game. By flipping through the same screenshot from both cards, we can quickly see if there's any differences. However, keep in mind that any differences present are actually quite normal, because these cards take different approaches (and make different compromises). Blurriness, sharpness, can easily be seen on a static image, but they are less noticeable in motion. Even more so when you're actually playing the game. That's why we categorize any differences between normal differences to noticeable differences.

However, static images often don't really capture aliasing or artifacts (such as shimmering) across different frames. The only way to do that is by showing it in real life on a monitor or a video. Of course, we opted to choose the video - we experimented with different screen capture software that will capture the artifacts we want to show and works 'good enough' with both cards. Unfortunately, that's not easy. We've finally settled on Hypercam, this software lets you screen capture your desktop (or a game) into an uncompressed, 32 bit RGB AVI file. Out of the games we used, only Homeworld 2 and SW: Knights of the Old Republic provide satisfactory results. This way we can provide you a glimpse (albeit in motion) of what we see during testing. In fact, these two games are perfect for this purpose (which we will get into later).

The second problem is showing you the file. Since the recording is a 1:1 pixel record in the form of an uncompressed 32 bit RGB AVI file, it takes lots of space (and bandwidth). A 5 second recording can take as much space as 50 MB. Compressing the video is not an option, since it introduced too much artifacts. After much trial and error, we've decided against using a video, instead making it available as a slide show. We actually extract each frame, in sequence, turn them into BMPs and put them inside a ZIP file that you can download. To view them, you can use a viewer (Windows Picture and Fax Viewer is actually perfect for this purpose), then just press and hold the right cursor button on the keyboard to advance to the next frame. It's just like moving the slider in your video player (frame by frame). However, we did have to made another compromise. The sequence from SW: Knights of The Old Republic was still too large, so we had to compress the BMPs into JPEGs. While there are compression artifacts, much of the aliasing (and lack of) is still very noticeable.

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