X-bit labs

ATI RADEON X800: R420 Totally Exposed

Category: Video

by Tim Tscheblockov , Alexey Stepin , Anton Shilov

[ 05/04/2004 | 06:42 AM ]

We take a look on the insides of ATI's just announced graphics processors RADEON X800 XT and RADEON X800 PRO. The new chips clearly have loads of interesting micro-architectural peculiarities that are likely to allow ATI's new lineup of graphics products to reach new performance heights in games, but that is not the only thing about the highly-acclaimed R420...

Table of contents:

• Introduction: The Battle Goes On
  
• RADEON X800 – New Graphics Card Family
  
• Power Consumption: Good News from ATI
  
• ATI R420: 8, 12 or 16 Pipelines?
  
• ATI RADEON X800 XT Platinum Edition and RADEON X800 PRO: Closer Look
  
• High Definition Gaming or Features and Peculiarities of RADEON X800 XT/PRO
  
• Pixel Pipelines, Pixel Shaders
  
• Vertex Pipelines, Vertex Shaders
  
• HyperZ HD
  
• VIDEOSHADER: Video and HDTV
  
• 3Dc: New Normal Maps Compression Algorithm
  
• Anisotropic Filtering
  
• Anisotropic Filtering: Performance
  
• Full-Screen Anti-Aliasing
  
• Full-Screen Anti-Aliasing: Performance
  
• Full-Screen Anti-Aliasing: Temporal Anti-Aliasing
  
• Drivers, Settings, and Testbed Configuration
  
• Performance of ATI RADEON X800 in Synthetic Benchmarks
  
• Synthetic Benchmarks: Fillrate tests
  
• Synthetic Benchmarks: Pixel Shaders
  
• Synthetic Benchmarks: Vertex Processors
  
• Synthetic Benchmarks: TnL
  
• Synthetic Benchmarks: Bump Mapping, Sprites, Etc.
  
• Conclusions for Synthetic Benchmarking Session
  

Introduction: The Battle Goes On

ATI Technologies and NVIDIA Corporation companies, two giants, who own the consumer 3D graphics market today are constantly involved in cut-throat competition: this fact is no secret for any more or less aware computer enthusiast. There certainly can be some periods of calm, when the rivals regain their power and exchange only a couple of tactical strikes, but as the new generation of graphics processors is released, a new round of confrontation gets started.

Not so long ago, about a month or so, ATI Technologies, which has got pretty secure positions in the market suffered a serious blow. NVIDIA announced a new graphics chip series also known as GeForce 6800/6800 Ultra and based on NV40 architecture, which got considerably improved compared with the previous NV3x generation and already managed to prove highly advantageous. So, ATI R360 graphics processor, which was at the top of the high-performance 3D graphics card series from ATI, immediately got ousted from the leader’s pedestal.

We didn’t have to wait for long for ATI to strike back. On May 4, 2004 the company finally put into life the well-prepared response. It’s new “weapon”, the new RADEON X800 series, is exactly the topic of our today’s discussion.

We will tell you more about the peculiarities and features of the new ATI architecture a little bit later, and in the meanwhile let’s take a closer look at the actual graphics cards we had in our testlab.

RADEON X800 – New Graphics Card Family

New graphics processor family from ATI aka R420 got a marketing name “RADEON X800”. You can interpret this name in many ways. Firstly, the Latin letter “X” makes the name sound very modern and very dynamic: “X” stands for “extreme”, extreme performance, extreme quality, etc. Secondly, “X” can also be read like a Roman number 10, which replaces the “9” in the previous generation graphics processor family: RADEON 9xxx. One way, or another, we consider this to be a very successful name for the new generation of graphics processors.

The new graphics card family from ATI based on R420 architecture will consist of three cards: RADEON X800 XT Platinum Edition; RADEON X800 PRO and RADEON X800 SE.

Having launched RADEON X800, ATI decided to split the graphics card family according to the performance differences between the chip modifications and to various pricing in a little bit different way compared to what they did before. If you remember, RADEON 9800 based graphics cards differed from RADEON 9800 PRO and RADEON 9800 XT mostly by the VPU and graphics memory clock frequencies. Now different models from the new RADEON X800 family will also differ by the number of pixel pipelines and memory bus width. You can use the table below to guide you through the differences between the three chips of the new RADEON X800 series:

As you can see from the table, R420 can work at much higher frequencies than its predecessors, or even NVIDIA NV40 (GeForce 6800/6800 Ultra).

Among a bunch of other factors that allowed achieving such high working frequencies, we should definitely keep in mind the importance of the fact that RADEON X800 is manufactured with 0.13micron low-k dielectric and copper compound technology.

The idea behind low-k dielectric technology implies that they use special material with low dielectric permittivity. The material is called “Black Diamond” and it allows reducing the spurious capacitances, which appear between the conductors connecting the functional units of the graphics processor located on die and thus reaching stable functioning at higher working frequencies. The reduction of dielectric permittivity also allows making the power consumption and heat generation much lower. The use of copper interconnects also serves the same purpose: copper boasts lower electric resistance than aluminum used in the old 0.15micron production process.