Core architecture

Like the RADEON 9500 PRO and GeForce 6600 GT, for RADEON X700, ATI has adopted an 8-pixel pipeline architecture, with one texture unit per pixel pipeline. This 8x1 pipeline configuration was previously used on all of ATI’s high-end cards, such as the RADEON 9700 PRO and 9800 XT, so ATI is essentially now bringing it down to the mainstream consumer. After all, today’s high-end cards now boast 12 or 16 pixel pipelines.

Unlike the high-end cards of yesteryear (or even the GeForce 6600 GT) however, the RADEON X700 family has one additional advantage going for it: ATI equips X700 with six vertex units, two more than RADEON 9700/9800 and matching the spec of ATI’s high-end X800 series.

With six vertex engines, X700 has twice the vertex power of GeForce 6600, and is capable of running over 5 billion vertex shader operations per second. ATI has released one technology demo that takes advantage of the added vertex power found in X700/X800: Crowd Demo. This demo involves a massive combat scene with a large number of characters on-screen at once (1,400 total). The added vertex power found in X700 and X800 allows these cards to render this sequence without a massive drain in performance, offloading work from the host CPU.

Screenshot from Lord of The Rings

Lots of soldiers on the screen at once in this Battle For Middle-Earth screenshot

Massive formation of troops

One shipping game that will take advantage of this is EA’s upcoming title “The Lord of The Rings: The Battle for Middle-Earth”. Like last year’s blockbuster movie, this game will have scenes with massive armies waging war with each other on the battlefield; the added vertex power found in X700 could yield a sizeable boost in performance. Other RTS titles will likely see similar benefits. Another title that should benefit is Far Cry, as vertex processing is used to render its lush jungle environments, with grass, trees, and other foliage found everywhere.

Huge battle here

Remember this scene from the movie?

Humans attack in this screenshot

X700 supports the same SMARTSHADER HD shaders as those found in X800. These are officially designated as 2.0b pixel shaders versus the 3.0 shaders NVIDIA supports in GeForce 6600/GeForce 6800. The key additions 2.0b brings over 2.0 is support for longer pixel shader programs, and more instructions (1,536 versus 160 previously). ATI has also improved their F-Buffer performance.

Like the X800, ATI has also integrated 3Dc support into X700. 3Dc provides up to 4:1 compression for normal maps, this increases performance and reduces memory footprint in titles that use normal maps. CryTek has committed to adding 3Dc support to Far Cry in an upcoming patch; Serious Sam 2 is another game that will take advantage of 3Dc. The core itself is built on TSMC’s 0.11-micron manufacturing process, just like GeForce 6600.

Connected to the graphics core is a 128-bit memory interface. This is the same size used on previous mainstream offerings such as the RADEON 9500 PRO/9600/9600 XT. By limiting the memory interface to 128 bits, board complexity is reduced keeping production costs down, but the tradeoff is reduced memory bandwidth. To keep the graphics core fed with data ATI uses high-speed GDDR3 memory on their X700 XT line, clocked at 525MHz. This provides over 16GB/sec of peak memory bandwidth, a figure which bests NVIDIA’s GeForce 6600 GT (which uses the same Samsung 2.0ns memory modules as the X700 XT).