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Compare any two graphics cards:
GeForce GTX 275 vs Radeon HD 3870 X2 1GB
IntroThe GeForce GTX 275 has a GPU core clock speed of 633 MHz, and the 896 MB of GDDR3 memory runs at 1134 MHz through a 448-bit bus. It also is comprised of 240 SPUs, 80 Texture Address Units, and 28 ROPs.
Compare all that to the Radeon HD 3870 X2 1GB, which comes with core speeds of 825 MHz on the GPU, and 1126 MHz on the 1024 MB of GDDR4 memory. It features 320(64x5) SPUs along with 16 TAUs and 16 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Theoretically, the Radeon HD 3870 X2 1GB should be a small bit faster than the GeForce GTX 275 in general. (explain)
Texel RateThe GeForce GTX 275 will be much (about 92%) faster with regards to texture filtering than the Radeon HD 3870 X2 1GB. (explain)
Pixel RateThe Radeon HD 3870 X2 1GB is a lot (about 49%) more effective at anti-aliasing than the GeForce GTX 275, and should be able to handle higher resolutions while still performing well. (explain)
Please note that the above 'benchmarks' are all just theoretical - the results were calculated based on the card's specifications, and real-world performance may (and probably will) vary at least a bit.
One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.
Please note that the price comparisons are based on search keywords - sometimes it might show cards with very similar names that are not exactly the same as the one chosen in the comparison. We do try to filter out the wrong results as best we can, though.
Memory Bandwidth: Memory bandwidth is the max amount of information (measured in MB per second) that can be transferred over the external memory interface in one second. The number is worked out by multiplying the bus width by its memory speed. If it uses DDR memory, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed per second. This number is calculated by multiplying the total texture units by the core clock speed of the chip. The higher the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly write to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the amount of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.