Texture Compression Explained

Sporting all the expected goodies for those OEM check-off lists, the Beast SC also offers a unique (read: proprietary) feature called S3 Texture Compression. Supported by Microsoft's DirectX 6, S3TC can compress a texture to one-fourth or one-sixth of its original size, and games supporting S3TC are able to use larger and more detailed textures for more engulfing gaming environments.

S3TC on one side, 8-bit palletized on the other.
Guess which one is smaller?

Earlier reviews of Savage3D cards barely skimmed the surface of what S3TC is capable of - they showed games such as Quake II and Unreal running with standard shipping texture-sizes, with zoom-in bubbles noting the most miniscule loss of detail from the compression process. From this, they claimed that S3TC was a worthless hack, and that the card required loss of visual detail to maintain a decent framerate.

Unfortunately, probably due mainly to miscommunication on both sides, the true nature and intent of S3TC - instead of compressing standard textures to increase speed, S3's compression technology is designed to allow for drastically increased texture detail and number of textures at little or no performance hit. The effectiveness of properly-implemented S3TC runs the gamut from "cool" to "Holy Cow!" Imaging walking right up into a wall - instead of hitting a blocky jumble of pixels, or a bilinear-filters mush of color, the texture instead becomes sharper and sharper, showing the grain on wooden slats or matte finish on a concrete wall. It's like wandering down to your local Good Guys and seeing HDTV for the first time.

Even at 256 colors, Large Q2 textures are impressive to behold

S3 even has special large Quake2 and Unreal maps with large textures showing the benefits of S3TC. You can find them here (http://www.s3content.com). The news3 and S3city Quake2 maps were very impressive even with the 256x256 texture size limit and 256-color texture palette. Note that what you see with Quake II subjectively reflects about 10% of what S3TC is capable of. An interesting note is that were actually able to load the news3 map just fine on our 16MB TNT, with smooth framerate. The reason? Even weighing in at 20MB for the S3city textures, Quake II doesn't allow for S3TC to strut its best stuff - 256x256 textures at 8-bit color can only go so far. For more on the texture compression story, we then turned to Unreal.