ATI Radeon X1900 XTX
ATI Radeon X1900 XTX reference board
The back of the card
The board design of ATIís own Radeon X1900 XTX card is the basis for all of the Radeon X1900 XTX cards weíre reviewing today, so weíll start with ATIís Radeon X1900 XTX card first, before moving on to the other manufacturers.
Why does everyone follow the ATI reference board design?
If you checked out the first picture in todayís roundup, you no doubt noticed that all of the Radeon X1900 XTX basically look the same, regardless of manufacturer. One of the more frequent questions we get around here whenever a new GPU from ATI or NVIDIA is released is why do all of the retail cards for a given GPU always look the same?
The answer is twofold actually. First, in order for graphics card manufacturers to receive ATI certification, they often have to adhere to certain rules and specifications dictating what they can and cannot do with their retail boards. Chief among them is that they canít adjust the clock speeds for the cardís graphics core and memory. In the NVIDIA card market, this form of factory overclocking is pretty commonplace, in fact in some cases youíre at a disadvantage if you donít do it. ATI on the other hand doesnít usually like their board partners to play with the rules, as their brand has been burned pretty badly in the process in the past because of this.
Back in earlier Radeon days, when the Rage 5 and Rage 6 were ATIís latest and greatest graphics processors, graphics and memory clock speeds on retail versus OEM graphics cards could vary wildly. In some cases by 20MHz or more. Adding to the confusion were parts from third-party board manufacturers that many consumers expected to have a 128-bit memory interface, but actually shipped with a narrower 64-bit memory interface. As you can imagine, chaos ensued once end users booted their cards up only to discover that their cards werenít running as expected. Ultimately ATI was forced to police their board partners more vigorously, launching the ďLEĒ moniker for these slower cards.
With the launch of the Radeon 9700 ATI really kicked things up a notch, forcing their board partners to purchase their 9700/9700 Pro cards directly from ATI rather than allowing the partners to make the boards themselves. The one board partner that did attempt to do things on their own, Tyan, got their chips so late that by the time their Tachyon G9700 Pro was ready to hit retail, ATIís faster Radeon 9800 was just around the corner. This brings us to the second reason why board partners stick with ATIís reference design: time-to-market.
Quite simply, in the time it would take a prospective card manufacturer to design/develop, manufacture, and adequately test their own custom solution, ATIís next part could be just weeks from release. This R&D process takes time, months in many cases, during that time you also risk losing sales to your competitors. Because of this, many card manufacturers are leery to take risks, especially on a higher-end part that can sell for a higher profit margin when itís first released.
We should note that this isnít always the case for all of ATIís GPUs. For the Radeon X800 GT/X800 GTO ATI gave their board partners quite a bit of leeway with their boards. Unfortunately, the X800 GT/X800 GTO market was a mess as a result, with boards shipping at a wide variety of clock speeds, and in the case of the X800 GTO, some with their pixel shaders disabled as ATIís reference specifications called for (for a total of 12), while others shipped from the factory with all 16 pixel shaders up and running.
The ATI Radeon X1900 XTX
ATIís Radeon X1900 XTX board design is actually largely based on its predecessor, the Radeon X1800 XT. ATIís Radeon X1900 XTX board uses the exact same PCB and cooling as the X1800 XT, although ATI and all of the other board manufacturers in this review use faster 1.1ns memory modules on their X1900 XTX cards instead of the 1.2ns modules that were used on X1800 XTs. Samsungís 1.1ns memory modules are officially rated for speeds up to 900MHz, while 1.2ns modules are rated up to 800MHz; considering that the memory on the Radeon X1900 XTX runs at 775MHz, on paper this leaves lots of headroom for overclocking. In practice though weíve found that X1900 XTX boards donít come anywhere close to hitting 900MHz when overclocking.
Other than the slightly faster memory modules, the only other change between the Radeon X1800 XT board design and the Radeon X1900 XTX is in power delivery. With 48 pixel shaders onboard and slightly higher clock speeds, the X1900 XTXís power requirements are a little higher than the X1800 XT and thus ATIís reference design calls for seven voltage regulators instead of the five that were used on Radeon X1800 XT 512MB cards (the Radeon X1800 CrossFire board actually shipped with six regulators).
Radeon X1800 XT (left) X1900 XTX (right) note the two additional regulators on XTX. You can also see that the XTX board also has more resistors than then X1800 XT
In terms of cooling, ATI outfits the X1900 XTX with a dual-slot cooler. The centerpiece of ATIís cooling solution is arguably the rather large copper heatsink used to draw heat off the graphics core and memory modules. Heat is drawn off these chips and then exhausted outside your systemís case thanks to ATIís blower-style fan. The fan has drawn some criticism from enthusiasts as it runs louder than previous cooling solutions from ATI, but it actually runs at different speeds depending on temperature.
At its lowest setting, the fan actually runs very quietly, itís actually nearly silent. At this setting, the fan spins at about 1700RPMs. This is the setting used for 2D desktop work. Once you load up a 3D app, the fan kicks up to its intermediate setting. Here the board generates more noise, although we wouldnít describe it as unbearable. It is however louder than NVIDIAís GeForce 7900 GTX.
Itís when the board is running at full tilt that it generates a considerable amount of noise. This occurs when the GPU is running at temperatures over 80 degrees Celsius. Fortunately we can report that the X1900 XTX rarely requires this level of cooling during use in single-card configurations; if your case is adequately cooled with good ventilation you should be okay, even when overclocking. Weíve hit the 80 degree threshold a few times when running two cards for CrossFire though.
Another board shot of ATI's X1900 XTX
In terms of connectivity, ATIís Radeon X1900 XTX (and all X1900 XTX cards for that matter, regardless of manufacturer) excels. ATI and their board partners provide two dual-link DVI connectors on the X1900 XTX, allowing the card to support resolutions as high as 2560x1600. Unlike retail GeForce 7900 GTX cards, the X1900 XTX also provides VIVO (video-in/video-out) functionality: all the Radeon X1900 XTX cards in this roundup are outfitted with ATIís Rage Theater chip to provide this functionality.
Software and accessories
Included inside the packaging of ATIís Radeon X1900 XTX are two DVI adapters, an S-Video cable, composite video cable, VIVO cable, and a component video cable. ATI doesnít include a game bundle with their cards, but you will get the driver CD and instruction manual with their X1900 XTX board.