HyperZ
Encyclopedia
HyperZ is the name of a set of computer graphics
Computer graphics
Computer graphics are graphics created using computers and, more generally, the representation and manipulation of image data by a computer with help from specialized software and hardware....

 processing techniques used by ATI Technologies
ATI Technologies
ATI Technologies Inc. was a semiconductor technology corporation based in Markham, Ontario, Canada, that specialized in the development of graphics processing units and chipsets. Founded in 1985 as Array Technologies Inc., the company was listed publicly in 1993 and was acquired by Advanced Micro...

 in their Radeon
Radeon
Radeon is a brand of graphics processing units and random access memory produced by Advanced Micro Devices , first launched in 2000 by ATI Technologies, which was acquired by AMD in 2006. Radeon is the successor to the Rage line. There are four different groups, which can be differentiated by...

 video card
Video card
A video card, Graphics Card, or Graphics adapter is an expansion card which generates output images to a display. Most video cards offer various functions such as accelerated rendering of 3D scenes and 2D graphics, MPEG-2/MPEG-4 decoding, TV output, or the ability to connect multiple monitors...

s.

On the Radeon R100
Radeon R100
The Radeon R100 is the first generation of Radeon graphics chips from ATI Technologies. The line features 3D acceleration based upon Direct3D 7.0 and OpenGL 1.3, and all but the entry-level versions offloading host geometry calculations to a hardware transform and lighting engine, a major...

-based cores, Radeon DDR through 7500, where HyperZ debuted, ATI claimed a 20% improvement in overall rendering efficiency. They stated that with HyperZ, Radeon could be said to offer 1.5 Gigatexels per second fillrate performance instead of the card's apparent theoretical rate of 1.2 Gigatexels. In testing it was shown that HyperZ did indeed offer a tangible performance improvement that allowed the less endowed Radeon to keep up with the less efficient GeForce 2 GTS.

With each new core, ATI has revised and improved the technology. In Radeon R200
Radeon R200
The Radeon R200 is the second generation of Radeon graphics chips from ATI Technologies. The architecture features 3D acceleration based upon Microsoft Direct3D 8.1 and OpenGL 1.3, a major improvement in features and performance compared to the preceding Radeon R100 design. The GPU also includes 2D...

 (8500-9250), HyperZ II was implemented. HyperZ III+ was used in Radeon R300
Radeon R300
The Radeon R300 is the third generation of Radeon graphics chips from ATI Technologies. The line features 3D acceleration based upon Direct3D 9.0 and OpenGL 2.0, a major improvement in features and performance compared to the preceding Radeon R200 design. R300 was the first fully Direct3D...

-based cards and HyperZ HD arrived with the Radeon R420
Radeon R420
The Radeon R420 core from ATI Technologies was the company's basis for its 3rd-generation DirectX 9.0/OpenGL 2.0-capable graphics cards. Used first on the Radeon X800, R420 was produced on a 0.13 micrometer low-K process and used GDDR-3 memory...

-based cards.

NVIDIA
NVIDIA
Nvidia is an American global technology company based in Santa Clara, California. Nvidia is best known for its graphics processors . Nvidia and chief rival AMD Graphics Techonologies have dominated the high performance GPU market, pushing other manufacturers to smaller, niche roles...

 introduced similar technology with the release of GeForce 3, called Lightspeed Memory Architecture (LMA). This technology eventually allowed the revamped NV17 core used on GeForce4 MX to outperform the GeForce2 Ultra (NV15) even though Ultra had twice as many pixel pipelines and the two were of the same family.

Functionality

HyperZ consists of three mechanisms:
  • Z Compression — The Z-Buffer is stored in a lossless compressed format to minimize the Z-Buffer bandwidth as Z read or writes are taking place. The compression scheme ATI used on Radeon 8500 operated 20% more effectively than on the original Radeon 256.

  • Fast Z Clear — Rather than writing zeros throughout the entire Z-buffer, and thus using the bandwidth of another Z-Buffer write, a Fast Z Clear technique is used that can tag entire blocks of the Z-Buffer as cleared, such that only each of these blocks need be tagged as cleared. On Radeon 8500, ATI claimed that this process could clear the Z-Buffer up to approximately 64 times faster than that of a card without fast Z clear.

  • Hierarchical Z-Buffer — This feature allows for the pixel being rendered to be checked against the z-buffer before the pixel actually arrives in the rendering pipelines. This allows useless pixels to be thrown out early (Early Z Reject), before the Radeon has to render them.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK