ATI’s Radeon X800 XL 512MB graphics card

What if you could get a 512MB graphics card for half that price?

Today ATI is announcing a 512MB flavor of its Radeon X800 XL. The card packs dual DVI outputs, video in and out capabilities, and twice the memory of the standard X800 XL for only $450. But does the extra graphics memory actually improve performance? We’ve run the Radeon X800 XL 512MB through its paces in an array of games and benchmarks to find out.

The card
As its name implies, the Radeon X800 XL 512MB is essentially a Radeon X800 XL with extra memory. The cards use the same 16-pipe RV430 graphics chip running at an identical 400MHz core clock speed, and they even share an effective 980MHz memory clock. You can read more about the Radeon X800 XL’s capabilities in our initial review of the card.

ATI’s Radeon X800 XL 512MB reference card

Despite their similarities, there are a couple of key differences between the 256MB and 512MB flavors of the Radeon X800 XL. Most obviously, the Radeon X800 XL 512MB has twice as many memory chips as the 256MB card. This dual-rank memory design allows ATI to endow the card with 512MB of memory without resorting to denser and more expensive memory chips. Accommodating the extra memory requires a board redesign, and apparently a little extra power. While Radeon X800 XL 256MB cards don’t require auxiliary power, our Radeon X800 XL 512MB reference card sports a six-pin PCI-E power connector.

Dual-rank memory from the rear

ATI has added more to the X800 XL 512MB than just extra memory, though. The 512MB card also comes with dual DVI outputs and Rage Theater-powered VIVO capabilities, neither of which are common on $300 Radeon X800 XL 256MB cards.

With a 50% higher price, it’s unlikely that the Radeon X800 XL 512MB will directly compete with 256MB versions of the X800 XL anyway. ATI expects the card to line up against NVIDIA’s GeForce 6800 GT, but with that card’s price hovering around $350 online, a more appropriate competitor may be the GeForce 6800 Ultra, which sells for as low as $500. And don’t forget the Radeon X850 XT, which can also be had for under $500.

Oh, and there’s one more wrinkle. ATI won’t actually be selling Radeon X800 XL 512MB cards itself. Instead, the card will be made available through ATI partners like Abit, Gigabyte, MSI, and Sapphire, with board shipments expected in late May. Each manufacturer will likely price its Radeon X800 XL 512MB as it chooses, depending on bundle contents and extra features. I wouldn’t expect them to all hit the market at the same time, either.

Our testing methods
All tests were run three times, and their results were averaged, using the following test system.

Today we’ll be looking at the Radeon X800 XL 512MB’s performance against that of the Radeon X800 XL 256MB and GeForce 6800 GT. Since all three cards have plenty of horsepower, we’ve only tested with antialiasing and anisotropic filtering enabled.

Thanks to OCZ for providing us with memory for our testing. If you’re looking to tweak out your system to the max and maybe overclock it a little, OCZ’s RAM is definitely worth considering.

Also, our test system was powered by OCZ PowerStream power supply units. The PowerStream was one of our Editor’s Choice winners in our latest PSU round-up.

We used the following versions of our test applications:

• DOOM 3 1.1 with trdelta1 and trhaze demos
• Far Cry 1.3 with tr1-volcano and tr3-pier demos
• Half-Life 2 with trboat and trtown demos
• Splinter Cell: Chaos Theory 1.02
• FutureMark 3DMark05 Build 120

The test systems’ Windows desktop was set at 1280×1024 in 32-bit color at an 85Hz screen refresh rate. Vertical refresh sync (vsync) was disabled for all tests. All of the 3D gaming tests used the highest possible detail image quality settings except where otherwise noted.

All the tests and methods we employed are publicly available and reproducible. If you have questions about our methods, hit our forums to talk with us about them.

Pixel filling power
Before we dive into our gaming tests, let’s have a look at the Radeon X800 XL 512MB’s theoretical peak fill rates and memory bandwidth to see where it sits in a crowded field of competitors. Theoretical peaks don’t always dictate real world performance, but they’re a good place to begin our analysis.

With identical core and memory clock speeds, the 256 and 512MB versions of the Radeon X800 XL are both nestled between the GeForce 6800 GT and Ultra. Of course, those are just theoretical peaks. 3DMark05’s fill rate tests measure actual single- and multi-texturing fill rate.

The X800 XLs trail the 6800 GT a little in the single-texturing test, which may be memory bandwidth-limited, but they pull ahead of the GeForce 6800 GT when laying down multiple textures. Note that there’s no difference in performance between the 256MB and 512MB versions of the Radeon X800 XL.

Moving to shader performance, the X800 XLs lead in both vertex shader tests, while the 6800 GT takes a win in the pixel shader test.

DOOM 3 – trdelta
We tested using DOOM 3’s High and Ultra Quality detail levels settings. Both enable 8X anisotropic filtering by default, but the latter turns off texture compression for specular and diffuse. According to id Software, the Ultra Quality detail level is meant for graphics cards with 512MB of memory, making it an ideal playground for the Radeon X800 XL 512MB.

Our first DOOM 3 demo explores single player gameplay in the Delta Labs.

The Radeon X800 XL 512MB’s extra memory has only a negligible impact on performance in this test. Scores are consistently higher with the 512MB card, but only marginally so. Both X800 XLs are slower than the GeForce 6800 GT, as well.

Doom 3 – trhaze
Our second DOOM 3 demo takes place in Hell, which is full of pixel shader-powered “heat haze” effects.

Again, 512MB of graphics memory appears to have no impact on performance, even with the Ultra detail level.

It’s worth noting that, while not reflected in our timedemo results, gameplay with DOOM 3’s Ultra quality setting is smoother on the Radeon X800 XL 512MB than with the 256MB card. 256MB graphics cards tend to stutter a little with DOOM 3’s Ultra quality mode, but the Radeon X800 XL doesn’t exhibit this behavior.

Far Cry
We used “Very high” for all of Far Cry’s in-game quality settings, with the exception of water, which was set to “Ultra high.” In other words, everything was maxed out.

Not much to see here. Although the X800 XLs best the 6800 GT in Far Cry, they don’t need 512MB of graphics memory do to it. Again, the frame rates of the X800 XL 256MB and 512MB flavors are nearly identical.

Half-Life 2
Half-Life 2 is loaded with massive textures, making it a perfect environment to test the benefits of 512MB of graphics memory. We tested performance with two custom demos that show off different parts of the game. In-game detail levels were set to their highest setting.

The X800 XL 512MB stretches its legs in Half-Life 2, offering better performance than the 256MB card, particularly at higher resolutions. The 256MB card’s frame rates are still quite playable, though, even at 1600×1200.

Splinter Cell: Chaos Theory
Splinter Cell: Chaos Theory is the newest addition to our graphics benchmarking suite, and it’s a looker. The game comes with a benchmark demo from the first level, which we’ve used for testing.

Chaos Theory is unique because it supports Shader Model 1.1 and 3.0, but not Shader Model 2.0 or any of its derivatives. The SM 1.1 and 3.0 code paths produce comparable images, although the 3.0 path offers extra eye candy, including HDR lighting, tone and parallax mapping, and soft shadows, that users can enable if they choose. Since the GeForce 6800 GT runs a little faster on the SM 3.0 code path, we’ve used that code path to test the card. There’s simply no reason to artificially handicap the GT’s performance with the SM 1.1 code path. The Radeon X800 XLs were tested with the SM 1.1 code path, which is how end users will have to run the game. Any extra SM 3.0 effects were disabled in order to maintain comparable image quality across all cards.

Extra memory doesn’t do much in Chaos Theory, where the Radeon X800 XL and the GeForce 6800 GT are evenly matched.

3DMark05 game tests
Finally, we have 3DMark05’s game tests.

3DMark05’s game tests don’t make much of a case for 512MB of graphics memory. The GeForce 6800 GT and the two Radeon X800 XL cards are pretty evenly matched here, too.

Turning it up to 11
With the exception of Half-Life 2, the Radeon X800 XL’s extra graphics memory seems to have little impact on performance. However, we’ve only been testing with 4X antialiasing and a mix of 8X and 16X anisotropic filtering, depending on game support. It’s possible to push the Radeon X800 XL 512MB even harder—namely, with 6X antialiasing, which the GeForce 6800 GT doesn’t support. In a last-ditch attempt to wring extra performance from 512MB of graphics memory, we ran the Radeon X800 XL 256MB and 512MB through a series of additional tests and forced 6X antialiasing and 16X aniso. The results are interesting from an academic standpoint, but in some cases, frame rates are lower than we’d consider playable.

Even with the highest available antialiasing and aniso settings, the Radeon X800 XL 512MB only has an advantage over its 256MB counterpart in Half-Life 2. The advantage is striking, but still limited to one title.

Power consumption
The Radeon X800 XL 512MB’s auxiliary power connector suggests that the card requires a little more juice than the 256MB card, so we busted out our trusty watt meter to measure system power consumption, sans monitor, at the outlet. Power consumption was measured at idle and under a load generated by 3DMark05’s first game test running at 1600×1200 with 4X antialiasing and 16X aniso.

Maybe the Radeon X800 XL 512MB doesn’t need that auxiliary power connector after all. Power consumption is a little higher than the Radeon X800 XL 256MB, but not by much. Both Radeon X800 XL cards exhibit lower power consumption than our GeForce 6800 GT.

Conclusions
The Radeon X800 XL 512MB’s extra 256MB of memory certainly improves performance, but only in Half-Life 2, and then most dramatically with 6X antialiasing and 16X anisotropic filtering. Otherwise, our test results don’t show much performance benefit from the extra memory apart from the elimination of stuttering in DOOM 3’s Ultra Quality mode. Those benefits are far from universal, especially since DOOM 3’s Ultra Quality mode doesn’t look all that much better than its High quality setting.

Of course, just because most current titles don’t take advantage of the Radeon X800 XL’s extra memory doesn’t mean that future games won’t. 512MB of graphics memory is an important milestone, and Half-Life 2 certainly indicates that the jump from 256MB can have a significant impact on performance. However, it’s up to game developers to exploit the extra memory. To date, few have.

According to ATI, games designed to take advantage of 512MB of graphics memory will be available in the next six to 12 months. By then, the next generation of graphics chips will be upon us, almost certainly with 512MB of memory at the high end and better performance overall.

Unless you’re a Half-Life 2 junkie, the Radeon X800 XL 512MB’s performance simply doesn’t justify the $150 price premium over its 256MB counterpart. The $300 Radeon X800 XL 256MB, where available at that price, is a pretty killer deal. Even if ATI’s board partners hit ATI’s projected price of $450, which they haven’t always done, the Radeon X800 XL 512MB will be lining up against much more formidable competition than the GeForce 6800 GT.