Matrox Parhelia-512 is a graphics processing unit (GPU) with full support for DirectX 8.1 and incorporating several DirectX 9.0 features. Released in 2002, it was best known for its ability to drive three monitors ("Surround Gaming") and its Coral Reef tech demo. As had happened with previous Matrox products, the Parhelia was released just before competing companies released cards that completely outperformed it. In this case it was the ATI Radeon 9700, released only a few months later. The Parhelia remained a niche product, and was Matrox's last major effort to sell into the consumer market. Background The Parhelia series was Matrox's attempt to return to the market after a long hiatus, their first significant effort since the G200 and G400 lines had become uncompetitive. Their other post-G400 products, G450 and G550, were cost-reduced revisions of G400 technology and were not competitive with ATI's Radeon or NVIDIA's GeForce lines with regards to 3D computer graphics. Description Features The Parhelia-512 was the first GPU by Matrox to be equipped with a 256-bit memory bus, giving it an advantage over other cards of the time in the area of memory bandwidth. The "-512" suffix refers to the 512-bit ring bus. The Parhelia processor featured Glyph acceleration, where anti-aliasing of text was accelerated by the hardware. Parhelia-512 includes 4 32×4 vertex shaders with dedicated displacement mapping engine, pixel shader array with 4 texturing unit and 5-stage pixel shader per pixel pipeline. It supports 16× fragment anti-aliasing, all of which were featured prominently in Matrox's Coral Reef technical demo. Display controller component supports 10-bit color frame buffer (called "Gigacolor") with 10-bit 400 MHz RAMDACs on 2 RGB ports and 230 MHz RAMDAC on TV encoder port, which was an improvement over its competitors. The frame buffer is in RGBA (10:10:10:2) format, and supports full gamma correction. Dual link TMDS is supported via external controller connected to the digital interface. Memory controller supports 256-bit DDR SDRAM. The "Surround Gaming" support allowed the card to drive three monitors creating a unique level gaming immersion. For example, in a flight simulator or sim racing, the middle monitor could show the windshield while the left and right monitors could display the side views (offering peripheral vision). However, only 2 displays can be controlled independently. Video cards The cards were released in 2002, simply called Matrox Parhelia, initially came with 128 or 256 MiB memory. Retail cards are clocked