Decreased memory size/bandwidth requirements = increased performance & better image quality
The obvious benefit that texture compression provides is that a given amount of texture data can be stored using significantly less memory. This is most critical when texturing out of the local frame buffer. Equally important is the fact that the memory and bus bandwidth required to read textures is greatly reduced, translating too much improved performance over AGP. System memory and AGP bus bandwidths are finite resources. With compression, the accelerator can take better advantage of these resources. As more compressed textures can be stored in local graphics memory, the use of local texturing is maximized. Reduced bandwidth also enables performance boost when texturing over AGP or from local frame buffer. The peak transfer rate for AGP-2x is 512MB/s. With 4x to 8x compression, you have the equivalent of 2.0GB/s to 4.0GB/s.
Larger and more numerous textures
Texture compression can allow for larger textures. While smaller, less detailed texture maps typically result in surfaces that look blurry or blocky, larger textures let the application provide more surface detail. Texture compression can also allow for a greater variety of textures to be used at any given time, permitting more varied scenes. When texturing out of local frame buffer memory, compression may free up enough memory to increase the display resolution or to perform triple buffering. A higher resolution display provides a smoother, more detailed look, while triple buffering can improve performance by allowing the rendering engine to start on a new scene without waiting for the display’s vertical sync. The use of triple buffering can result in a significant increase in frame rate (typically 30%).
Mip-mapping
The extra memory available with compressed textures allows for the use of Mip-maps even with the added memory storage required (30%) over the base texture map level. Mip-maps help to reduce aliasing artifacts visible on textured surfaces that span significant distances. Without Mip-maps, a pixels on an object far away may be associated with several texels from the original texture map. Low-pass filtering is used to retain the information, while not introducing unwanted artifacts (shimmering, crawling pixels). Real time filtering is expensive, so staged Mip-map levels can be used that are pre-computed filtered images, dramatically lowering the filtering complexity.
The obvious benefit that texture compression provides is that a given amount of texture data can be stored using significantly less memory. This is most critical when texturing out of the local frame buffer. Equally important is the fact that the memory and bus bandwidth required to read textures is greatly reduced, translating too much improved performance over AGP. System memory and AGP bus bandwidths are finite resources. With compression, the accelerator can take better advantage of these resources. As more compressed textures can be stored in local graphics memory, the use of local texturing is maximized. Reduced bandwidth also enables performance boost when texturing over AGP or from local frame buffer. The peak transfer rate for AGP-2x is 512MB/s. With 4x to 8x compression, you have the equivalent of 2.0GB/s to 4.0GB/s.
Larger and more numerous textures
Texture compression can allow for larger textures. While smaller, less detailed texture maps typically result in surfaces that look blurry or blocky, larger textures let the application provide more surface detail. Texture compression can also allow for a greater variety of textures to be used at any given time, permitting more varied scenes. When texturing out of local frame buffer memory, compression may free up enough memory to increase the display resolution or to perform triple buffering. A higher resolution display provides a smoother, more detailed look, while triple buffering can improve performance by allowing the rendering engine to start on a new scene without waiting for the display’s vertical sync. The use of triple buffering can result in a significant increase in frame rate (typically 30%).
Mip-mapping
The extra memory available with compressed textures allows for the use of Mip-maps even with the added memory storage required (30%) over the base texture map level. Mip-maps help to reduce aliasing artifacts visible on textured surfaces that span significant distances. Without Mip-maps, a pixels on an object far away may be associated with several texels from the original texture map. Low-pass filtering is used to retain the information, while not introducing unwanted artifacts (shimmering, crawling pixels). Real time filtering is expensive, so staged Mip-map levels can be used that are pre-computed filtered images, dramatically lowering the filtering complexity.
