Matrox – Parhelia 512 review

128MB high-performance 3D graphics card
Photo of Matrox – Parhelia 512

For a long time it seemed that Matrox was content to leave the high-performance 3D graphics card market to others, instead concentrating on mainstream ‘DualHead’ business chipsets. But now that’s changed, with a totally new chipset and a radical new card, the Matrox Parhelia 512, on sale with 128MB of memory.

The Parhelia 512 is the world’s first 512-bit GPU (Graphics Processor Unit) and the first to implement a 256-bit DDR memory bus for a graphics processor. This is a big chip, with a 0.15 micron manufacturing process and 80 million transistors. To give you an idea of this size, its nearest competitor, the Nvidia GeForce 4 Ti, has 63 million transistors, while a Pentium 4 Northwood CPU has about 57 million transistors. The Parhelia 512 has a 220MHz core clock speed and a 275MHz DDR memory clock, allowing for a memory bandwidth up to an amazing 17.6GB/s.

Incorporated into the chip are four parallel DirectX 9-compatible vertex shader units, which are joined into a single vertex-processing array. With this array of vertex shaders, the Parhelia-512 is able to sustain very high performance levels even when it is executing complex vertex shader programs on high-resolution 3D models. The Quad Vertex Shader array is claimed to give up to 100 Megatransforms per second and it supports the latest Vertex Shader version 2.0.

Another first for the Parhelia 512 is the quad pixel quad texturing feature (4×4 texturing). As with the GeForce4 and the Radeon 8500, there are four pixel pipes. But unlike the Nvidia and ATI chips, there are four texture stages per pipe, not two. With this, four textures on four pixels can be rendered simultaneously in a single pass, greatly enhancing performance throughput, especially when a game requires the GPU to perform complex quad texturing.

To add to the growing number of anti-aliasing techniques used by ATI and Nvidia, Maxtor has introduced 16x Fragment anti-aliasing (FAA-16x). Currently the most popular form of anti-aliasing is based on Full-Scene anti-aliasing (FSAA). With 2x or 4x FSAA, any given frame is rendered internally at twice or four times its original resolution in order to obtain two or four colour samples of each edge pixel (supersampling).

These samples are then blended together when the scene is rendered back down to the output resolution, blurring the jagged lines and giving the illusion of a straight edge. 16x Fragment anti-aliasing works by examining the edge pixels of each triangle for fragmented pixels (essentially pixels overlapping the edge of the object they are rendered onto), using 16x supersampling to break each pixel down into a 4×4 grid and then determining which pixels lie partially outside the boundaries of the object.

Data on the fragmented pixels is then written to a special fragment buffer, while the rest of the pixels go to the frame buffer, ready for output. The pixels in the fragment buffer are then anti-aliased using the same methods as FSAA except at 16x the original resolution, then written back to the frame buffer to achieve the anti-aliased output.

Got that? Basically, this all means that the card can generate high quality graphics output at fast frame rates, which is all that really matters.

With more companies following its lead and offering dual display options, Matrox has gone one better with the Parhelia, with its new TripleHead feature. Not only can you span your desktop display to three independent monitors, but it also allows 3D games graphics to be rendered across all the three monitors at the same time – Matrox calls this ‘Surround Gaming’.

In desktop mode, business users or professional graphic designers will once again enjoy an expanded view of their desktop, but instead of a single display for multiple windows, it’s now possible to have multiple windows on multiple display screens. DualHead is still supported and the Parhelia 512 supports resolutions up to 2,048 pixels by 1,536 pixels on each analog monitor. For LCD panels this drops to 1,920 pixels by 1,200 pixels for each panel.

Company: Matrox

Contact: 01753 665500

Time will tell if the Matrox Parhelia 512 has what it takes to take away the top slots from Nvidia and ATI, but it is certainly quick. It also has some interesting technologies built into it and the Triple Head feature hands the lead in multi-display capability back firmly to Matrox.