The PC market is an unforgiving, what-have-you-done-for-me-lately place, as ATI is well aware: The company’s been playing second fiddle to nVidia for almost two years now. Still, ATI has introduced its share of innovations—Avivo, 512MB frame buffers, and 48 pixel shaders among them—and now it finally has the fastest single-GPU videocard.
It’s important to note, however, the distinction between a single-GPU videocard and a single videocard. nVidia’s dual-GPU GeForce 7950 GX2 remains the performance leader in the latter category; but the X1950 XTX is no slouch. This is the first consumer videocard to feature 512MB of GDDR4 RAM, clocked at a blistering 1GHz. Good thing, too, because the GPU, which ATI has dubbed the R580+, is not radically different from the X1900 XTX: It has the same number of pixel shaders (48), the same number of vertex shaders (8), and the same core clock speed (650MHz).
The fan on ATI’s X1900 XTX is loud enough to wake the dead, so ATI wisely adopted a new cooling design—one that’s very similar to HIS’ IceQ Radeons—for the X1950 XTX: a ginormous copper heatsink covering the GPU and memory, and a very large fan (7.25cm) mounted far back on the card. The X1950 XTX GPU still runs considerably warmer than nVidia’s GeForce 7900 GTX—by about 15 C under load—but thanks to this new cooling design, the card produces very little fan noise: It’s easily as quiet as nVidia’s 7900 GTX.
ATI has also introduced an X1950 CrossFire Edition, which unlike the X1900 CrossFire, has an identical core clock speed (the previous top-end master card runs 25MHz slower than its mate). Unfortunately, anyone interested in building a dual-Radeon rig remains saddled with ATI’s unappealing external cable connection. And as with nVidia’s SLI, running in CrossFire mode shuts down the second display in dual-head configuration. ATI hasn’t figured out how to play video using CrossFire, either; you must disable it for DVD playback. On the bright side, the card supports HDCP copy protection through its DVI ports, which makes it an eligible partner for next-gen optical drives.
When we unlocked and overclocked the X1950 XTX using the utility built into ATI’s Catalyst Control Center, the software goosed the GPU’s core clock speed to 668MHz, but it didn’t increase the speed of the memory at all. In any event, the speed bump didn’t have much impact on performance: The performance increased just 3 percent, at most. In single-card mode, the X1950 XTX is significantly faster than a reference-design 7900 GTX in some of our benchmarks, moderately faster in others, and slower—by one frame per second—in one (refer to the benchmark chart for details).
ATI is proud of the fact that its X1000 cards can perform high dynamic-range lighting and antialiasing at the same time—nVidia’s cards can’t. But the value of such a feature is diminished by the performance hit the card takes to deliver it. Turning on 4x AA in our 3DMark06 HDR tests resulted in a 19 percent reduction in frame rate in Game 1, and a 38 percent drop in Game 2.
So, the X1950 XTX is the fastest single-GPU card out there. Should you drop four and a half bills on one? Frankly, it’s tough for us to recommend dropping that kind of green on any DirectX 9 videocard right now, simply because DirectX 10 is waiting in the wings. Think of it this way: If you buy this card today, and DX10 comes out as late as April 2007, will it have delivered $100 per month of value by then? —Michael Brown
Month Reviewed: November 2006
+ HOT BOX: Faster than Nvidia's best single-GPU cards; HDCP compatible.
- CAT BOX: Not the fastest single videocard; late in the game for a high-end DX9 card.