While ATI has introduced a new high-end product roughly every 6-9 months pretty routinely for the past few years, as you probably know, each of these new graphics cores has been fundamentally a follow-up part to ATIís RADEON 9700 graphics card first introduced in the summer of 2002. The RADEON 9800 and 9800 XT families were both more of the same, only with higher clocks, while the X800 series added 2.0b shaders, more pipelines, a new manufacturing process with higher clock speeds, and other goodies such as temporal AA and 3Dc.
Sure, each of these follow-up cards delivered substantially more performance than ATIís original RADEON 9700 PRO, but ATI didnít exactly reinvent the wheel in the process. Ultimately this was beginning to catch up with them as an increasing number of shader model 3.0 titles have shipped in the past six months (fortunately for ATI they were largely able to get around this dilemma with clever patches for the most prominent titles that added 2.0b shader support).
With RADEON X1800, all that has changed, as the R520 VPU itís based on has been built from the ground up on an entirely new architecture. Letís take a look at the specs:
90 Nanometer Technology
Faster clock speeds
Double the transistor density of earlier 130nm technology
320 million transistors
New Performance Architecture
High efficiency Ultra-Threaded Pixel Shader Engine
Supports Shader Model 3.0 at speeds several times faster than any existing
16 pixel pipelines
8 vertex pipelines
625MHz graphics core with 256MB or 512MB of GDDR3 memory at 1.5GHz on RADEON X1800 XT
New Memory Controller Design
Supports the fastest available memory speeds
512-bit internal ring bus
New cache design, improved HyperZ, latency improvements
Next-Generation Image Quality
Advanced High Dynamic Range rendering with anti-aliasing supported, 128-bit floating point precision
New adaptive anti-aliasing mode combines image quality of supersampling with speed of multisampling
New high quality anisotropic filtering mode
Revolutionary display, video, and connectivity capabilities
Consumer electronics convergence features
Powerful parallel graphics processing support
Arguably the most notable items that stood out from the specifications list above are the X1800 XTís high clock speeds (600MHz+, roughly 200MHz faster than GeForce 7800 GTX) and the number of pipelines. After rumors speculating that R520 boasted 24 or even 32 pixel pipelines, we now see that the chip sports the same number of pipelines as its predecessor (with one texture unit per pixel pipeline), although with approximately 320 million transistors inside (twice that of the RADEON X800 from a year ago), ATI obviously incorporated quite a few new features into R520. ATI is quick to point out that RADEON X1800 supports HDR with multisample AA; a feature which NVIDIA currently doesnít provide with any of their GPUs. Apple Cinema display users will also be happy to know that the RADEON X1800 XT supports dual-link DVI.
Of course, with a new architecture comes new nomenclature to read up on. With that in mind, lets quickly go over a few of the most notable changes ATI has integrated into the RADEON X1800.