Advanced Micro Devices Tuesday unveiled a graphics card, the ATI Radeon HD 4870 X2, that is widely expected to outperform rival Nvidia's top-end graphics card, the GeForce GTX 280.

Priced at $549, the 4870 X2 is currently available and will be followed by release of the $349 ATI Radeon HD 4850 X2 in September, AMD said. Both cards have dual graphics processors that are linked using the company's CrossFireX technology and a dedicated bridge chip. CrossFireX allows multiple graphics processors to work in tandem, offering a significant boost in graphics performance.

"We did some driver work, along with this bridge chip, to make this somewhat seamless," said Pat Moorhead, vice president of advanced market at AMD. "That took a lot of work."

The graphics chips used on the 4870 X2 run at clock speeds of 750MHz, while the chips used on the 4850 X2 run at 625MHz. Another difference lies in the graphics memory used on the two cards. The 4870 X2 has 2G-bytes of GDDR5 (graphics double data rate 5) memory, while the 4850 X2 has 2G bytes of GDDR3 memory.

AMD offered a taste of the graphics capability of the 4870 X2 in June, showing reporters at the Computex exhibition a brief, but very realistic-looking, clip of the company's female mascot, Ruby, being chased down a city street by a four-legged robot. The clip was rendered in real time, AMD executives said.

The use of two GPUs is what gives the 4870 X2 an edge over Nvidia's GTX 280, which was released in June and has a single graphics chip.

In a comparison of the GTX 280 and AMD's ATI Radeon HD 4870 and 4850 -- which have single graphics chips -- conducted by hardware-enthusiast site TechSpot, the Nvidia card outperformed the top-end AMD card. But add another GPU to the 4870 X2 and AMD will likely have a healthy edge over Nvidia's latest offering.

The release of the 4870 X2 and 4850 X2 reinforces the strong graphics capability that AMD bought when it acquired ATI. ATI and Nvidia have long dominated the graphics space and their high-end technology easily outpaces the graphics technology found in Intel's integrated chipsets.

The technology used in the 4870 X2 will likely find its way into other AMD products. One possibility is that a similar graphics processor could be used in Fusion, a family of chips that AMD plans to release starting next year. Fusion processors will incorporate a graphics core into a microprocessor, a feature that AMD is counting on to increase the competitiveness of its future products. However, AMD has yet to reveal what graphics technology will be used in Fusion.

The IDG News Service is a Network World affiliate.