SAN JOSE, Calif. Advanced Micro Devices rolls out today (May 14) a next-generation graphics architecture that, at least on paper, leapfrogs on several fronts its archrival, the Nvidia GeForce 8800 released last fall. AMD's HD 2900 uses more advanced process technology, has unique hardware capabilities and in one configuration supports a faster memory bus than the Nvidia part.
Since its November release, Nvidia has enjoyed an unusually long time-to-market advantage over its archrival ATI Technologies, now the graphics division of AMD. Analysts are holding off calling a winner in the latest generation until they can benchmark both chips, but they say it's clear AMD is at least standing toe-to-toe with its competitor again.
The AMD HD 2900 will come in versions made in 80nm and 65nm CMOS and offer a pool of as many as 320 arithmetic logic units. By comparison, the Nvidia devices are made in a 90nm process and offer an array of 128 ALUs.
In addition, a high end version of the new AMD architecture will sport a 512-bit wide memory interface to GDDR4 graphics memory. In its latest generation, Nvidia is only linking to GDDR3 memory with interfaces no wider than 400 bits.
"If you had to pick on thing to define the performance of a graphics accelerator, the memory interface is the best indicator," said Dean McCarron, principal of market watcher Mercury Research (Cave Creek, Ariz.). He added that it's especially unusual for the two companies to part ways over which memory technology they use.
Internally, AMD distinguishes its memory interface with a 512-bit memory controller laid out as a ring bus around the periphery of the chip. AMD says the distributed controller will be highly scalable because it requires no central hub. It supports up to eight 64-bit memory channels in the new generation.
The ring bus new ring bus simplifies the chip's routing and reduces wire delay as well as the need for repeaters, sat Matt Skynner, vice president of marketing for the AMD graphics group.
The HD 2900 also includes a specific hardware acceleration pipeline for tessellation. The feature enhances the chip's ability to support finely detailed features and shadows.
Hardware support for high definition video playback is a cornerstone for both the latest AMD and Nvidia accelerators. One way AMD is distinguishing its part's HD capabilities is through supporting an integrated controller for the High Definition Multimedia Interface (HDMI).
The chip includes a block that supports both HDMI video and audio. It also includes a bank of ROM for handling the keys used in HDMI content protection. Many existing devices require external HDMI audio controllers and ROM for the content protection keys.