45 lines
2.6 KiB
Plaintext
45 lines
2.6 KiB
Plaintext
#summary Real-Time DXT Compression
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The compressors available in the NVIDIA Texture Tools are not designed for real-time compression. If you need to compress textures in real-time, I'd recommend to look at the following sources:
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[http://mrelusive.com J.M.P. van Waveren] was the first one to describe a [http://www.intel.com/cd/ids/developer/asmo-na/eng/dc/index.htm real-time DXT compressor]. This compressor is part of the of [http://softwarecommunity.intel.com/UserFiles/en-us/Image/1221/Real-Time%20Texture%20Streaming%20&%20Decompression.pdf real-time texture streaming pipeline] used in some [http://www.idsoftware.com id Software] games. He obtains the following results with his SSE2 optimized implementation:
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|| *CPU* || *DXT1* || *DXT5* ||
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|| Intel 2.8 GHz Dual Core Xeon || 112.05 MP/s || 66.43 MP/s ||
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|| Intel 2.9 GHz Core 2 Extreme || 200.62 MP/s || 127.55 MP/s ||
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The same algorithm described by Waveren can also be adapted easily to the GPU. This is what Simon Green did in [http://developer.download.nvidia.com/SDK/10/opengl/samples.html#compress_DXT this OpenGL SDK example]. The performance on the GPU is much more impressive:
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|| *GPU* || *DXT1* || *DXT5* ||
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|| !GeForce 8800 GTX || 1,547 MP/s || - ||
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|| !GeForce 8600 GTS || 461 MP/s || - ||
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A later [http://developer.nvidia.com/object/real-time-ycocg-dxt-compression.html whitepaper] by Waveren and [http://castano.ludicon.com Ignacio Castaño] provides even higher results on the GPU:
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|| *GPU* || *DXT1* || *YCoCg-DXT5* ||
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|| !GeForce 8800 GTX || 1,690 MP/s || 939 MP/s ||
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|| !GeForce 8600 GTS || 520 MP/s || 279 MP/s ||
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Peter Uliciansky optimized Waveren's algorithm further and published his results in this thread: [http://developer.nvidia.com/forums/index.php?showtopic=1737 Extreme DXT Compression, New algorithm for real-time DXT compression].
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|| *CPU* || *DXT1* || *DXT5* ||
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|| Intel Pentium 4 2.8 GHz || 241.2 MP/s || 206.5 MP/s ||
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|| Intel Core 2 3.0 GHz || 910.0 MP/s || 620.4 MP/s ||
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These numbers are very impressive and start to get closer to the results of the GPU implementation.
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However, the latest GPU implementation also offers higher performance.
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* http://developer.download.nvidia.com/SDK/10/opengl/samples.html#compress_YCoCgDXT
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* http://developer.download.nvidia.com/SDK/10/opengl/samples.html#compress_NormalDXT
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|| *GPU* || *DXT1* || *YCoCg-DXT5* || *BC5* || *DXT5n* ||
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|| !GeForce 8800 GTX || 3450 MP/s || 1880 MP/s || 5665 MP/s || 5804 MP/s ||
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|| !GeForce GTX 280 || 9920 MP/s || 7900 MP/s || 12850 MP/s || 13150 MP/s ||
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Other links:
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* https://mollyrocket.com/forums/viewtopic.php?t=392
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* http://www.evl.uic.edu/cavern/fastdxt/ |