Benefits of SGRAM


State-of-the art SGRAM
For mainstream business and consumer PC applications requiring acceleration at mid-range resolutions and color depths, new single-ported memory types like SGRAM (Synchronous Graphics RAM) provide the most cost effective solution.

Most mainstream 2D, 3D and even video applications require support for 8 or 16-bit color at high resolutions. Support for 24-bit color at resolutions above 1152 x 882 are needed mostly for professional applications like graphics design and CAD. These high-end applications require dual-ported memories like WRAM to enhance performance. For mainstream users, there is little or no incentive to pay for high resolution 24-bit color when it will never be taken advantage of.

However, today’s new graphics, digital video and 3D games are still computationally intensive and require the aid of powerful memory types to accelerate performance. New single-ported memory technologies have emerged to attempt this difficult task but none have been able to beat the price/performance offered by SGRAM.

In the case of all single-ported memories, the bandwidth available for graphics operations will drop continually as resolutions, color depths and refresh rates rise. This is because the drawing engine has to wait for the screen to be refreshed before it can write to the frame buffer, and the more time taken to redraw the screen, the longer the engine has to wait.

Even though SGRAM is a single-ported memory, it is less effected by declining bandwidth than other single-ported memories such as (EDO DRAM), Rambus DRAM (RDRAM), MoSys DRAM (MDRAM) and Synchronous DRAM (SDRAM). SGRAM is a new memory type capable of being clocked at considerably higher speeds than traditional single-ported memories. For example, this difference is illustrated by the following chart: Available Graphics Engine Bandwidth after Display Refresh as measured in MBytes/second*

Resolution EDO DRAM SGRAM
1024x768@8bpp 312 340
1024x768@16bpp 220 280
1024x768@24bpp 152 236
1280x1024@24bpp NS 124


Matrox Mystique
Matrox Mystique uses SGRAM memory to provide high bandwidth and accelerated graphics-specific features to accommodate the demands of today’s new graphics, 3D and video applications.

Among all single-ported memory types, SGRAM best combines the raw bandwidth (speed) and graphics-specific features, such as block writes and dual bank support, for the highest overall graphics performance.

The dual bank feature opens two pages of memory at the same time, which accelerates operations such as screen to screen blts (copying), double-buffering, 3D rendering and video playback.

In addition, SGRAM’s single-color-block write feature accelerates screen fills and clears at up to 8 times the speed of EDO DRAM. The block write feature can be used for fast patterning and text draw. This accelerates Windows applications, Word documents, Excel spreadsheets and more. Also, these screen fills are extremely important elements in accelerating the 3D pipeline as 3D intensity and Z buffers must be cleared 30-40 times each per second.

Dual bank and single color block write are unique features of SGRAM that are fully exploited by Matrox Mystique’s graphics engine.

The Mystique also integrates a 170 MHz RAMDAC within its graphics chip. This eliminates the need for an external RAMDAC, thus substantially lowering the cost and space required for the graphics sub-system.

MGA-1064SG chip technology
At the core of Matrox Mystique is the MGA-1064SG graphics chip. This fifth generation 64-bit chip combines acceleration for 2D, 3D, video, and a 32-bit VGA core. When combined with SGRAM memory and a superior PCI bus interface, MGA-1064SG delivers outstanding performance in an all-in-one low cost solution. Matrox Mystique meets the demanding needs of mainstream business and consumer applications with acceleration for general Windows, 3D texture mapped games, smooth digital video playback, accelerated 3D Web browsing, and DOS games.

State-of-the art WRAM
Professional, high-end graphics applications require maximum acceleration and refresh rates in ultra high resolutions and color depths. These demands push the requirements of the memory bandwidth of graphics engines to the limits. To meet the demands of professional graphics users, dual-ported memory types are required.

Dual-ported memory types contain two ports allowing graphics drawing operations to process simultaneously while the display is being refreshed. This doubles the available bandwidth and makes performance less dependent on resolution, color depth and refresh rates. Single- ported memory types, such as EDO DRAM, SGRAM and SDRAM, are not well suited for high-end graphics because they are unable to provide enough bandwidth to sustain high performance at high resolutions, color depths and refresh rates.

Professional graphics applications consume massive amounts of memory bandwidth just to refresh the display. For instance, at 1280 x 1024@24bpp at 85Hz refresh, over 80% of the bandwidth of EDO DRAM is spent on display refresh, leaving little time to actually draw graphics. Therefore, dual- ported memory is the only type that can sustain high performance.

Only two dual-ported memories are popular on the market today; Video RAM (VRAM) and Window RAM (WRAM). WRAM is far superior because it provides a maximum bandwidth over 25% higher than the ‘old school’ VRAM. The total bandwidth available from a well balanced WRAM solution is over 1 GB/sec of memory bandwidth.

Additionally, WRAM is designed specifically for graphics and has a number of extra graphics features that are lacking in VRAM. Unique features include dual-color block-write mode for fast acceleration of text and fills for high resolution documents, and accelerated aligned BitBLT’s (copying information from one part of the graphics frame buffer to another) at 8X the performance over VRAM for fast and smooth double buffering. Finally, WRAM offers better price/performance than VRAM because it uses less circuitry.

Matrox Millennium
When designing a graphics board, a manufacturer must decide whether a product will be optimized for a specific type of memory, or if it will be compatible with multiple memory types. To take full advantage of special functions in a particular memory technology, the graphics engine must integrate a memory controller specific to the memory chosen.

Matrox is the only manufacturer that has taken the extra step in designing the WRAM controller in the MGA-2064W graphics chip found in the Matrox Millennium graphics accelerator.

Millennium’s use of WRAM makes it the ideal solution for high-end, professional applications because it maintains high system performance as resolutions, color depths and refresh rates are increased to the maximum. Millennium is also upgradeable to 8 MB of memory, enabling users to work in true 24-bit color at 1600 x 1200 resolution without experiencing a significant drop in performance. Its dual-ported WRAM memory also ensures high refresh rates at ultra high resolutions because it refreshes the screen at the same time it processes data, drastically reducing screen flicker.

Price Performance
Matrox Millennium offers the best price/performance because it uses inexpensive WRAM technology. WRAM costs 20% less per bit than its lone dual-ported competitor VRAM. Only two chips are needed to create a 2 MB frame buffer as opposed to 4 in the case of VRAM and DRAM. Further, the onboard Z-buffer is stored in offscreen WRAM so that no dedicated Z-buffer memory is required, also minimizing board cost.

MGA-2064W chip technology
Besides the advantages of WRAM, Matrox Millennium uses the industry’s most powerful and complete graphics chip. The MGA-2064W 64-bit graphics chip integrates acceleration for Windows, video, 3D and DOS This all-in-one graphics board is the ideal solution for professional applications like high resolution spreadsheets and document imaging, desktop publishing, illustration and photo retouching, 2D and 3D CAD/animation, and corporate digital video training. In addition, the Millennium uses a powerful 220 MHz RAMDAC to deliver ultra high refresh rates at high resolutions.

Speed Features Benefits
Fast 50MHz memory 960MG/sec bandwith
8 mbit technology Only 2 chips needed for 2MB frame buffer vs 4 chips with VRAM
Unique Features Benefits
Dual-Ported memory Can process graphics drawing and screen refresh simultaneously
Supports dual-color block-write mode Fast text and color fills
Aligned bit Fast scrolling and page flips





Bottom toolbar
Copyright © 1996 Matrox Graphics Inc. All rights reserved.
Send all questions and comments regarding this site's construction to webmaster@matrox.com