Cirrus Logic - Graphics History

Graphics History

In the early 1990s, Cirrus Logic was a leading supplier of low-cost PC graphics chips. Cirrus's Microsoft Windows 2D GUI accelerators (GDI) were among the fastest in the low-end market-segment, outperforming competing VGA-chips from Oak Technologies, Trident Microsystems, and Paradise (Western Digital). For example, the Cirrus GD5422 (1992) supported hardware acceleration for both 8-bit color and 16-bit color. It was one of the lowest-priced SVGA controllers to support both.

By the mid-1990s, when PC's had migrated to the PCI bus, Cirrus had fallen behind S3 and Trident Microsystems. When the announced release date of the GD5470 "Mondello" came and went, Cirrus's reputation in desktop PC-graphics suffered. (Mondello would have been the company's first 3D-accelerator, but instead became vaporware.)

The company's final graphics chips, the GD546x "Laguna" series of PCI/AGP 3D-accelerators, were novel in that they were one of the few video cards to use Rambus RDRAM. However, like many other 2D/3D chips at the time, the feature set of perspective-correct texture mapping, bilinear filtering, single-pass lighting, gouraud shading, and alpha blending, was both slow and incomplete.

Emulated Cirrus Logic graphic cards are used in emulators. QEMU emulate the Cirrus CLGD 5446 PCI VGA-card, which is also emulated by the Xen-HVM and KVM.