Compare any two graphics cards:
GeForce 9800 GTX+ vs Radeon HD 3870 X2 512MB
IntroThe GeForce 9800 GTX+ features core clock speeds of 738 MHz on the GPU, and 1100 MHz on the 512 MB of GDDR3 RAM. It features 128 SPUs along with 64 TAUs and 16 ROPs.
Compare all of that to the Radeon HD 3870 X2 512MB, which makes use of a 55 nm design. AMD has set the core speed at 825 MHz. The GDDR3 RAM works at a frequency of 900 MHz on this particular model. It features 320(64x5) SPUs as well as 16 Texture Address Units and 16 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Theoretically speaking, the Radeon HD 3870 X2 512MB will be 64% faster than the GeForce 9800 GTX+ in general, because of its higher data rate. (explain)
Texel RateThe GeForce 9800 GTX+ will be a lot (about 79%) more effective at texture filtering than the Radeon HD 3870 X2 512MB. (explain)
Pixel RateThe Radeon HD 3870 X2 512MB will be a lot (approximately 124%) better at anti-aliasing than the GeForce 9800 GTX+, and capable of handling higher screen resolutions without losing too much performance. (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 maximum amount of data (counted in megabytes per second) that can be moved past the external memory interface in one second. The number is worked out by multiplying the interface width by its memory speed. If it uses DDR type RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied per second. This is calculated by multiplying the total texture units of the card by the core speed of the chip. The better the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly record to its local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the number of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.