Compare any two graphics cards:
GeForce 9800 GTX+ vs Radeon HD 4850 X2 512MB
IntroThe GeForce 9800 GTX+ has 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 Texture Address Units and 16 Rasterization Operator Units.
Compare all of that to the Radeon HD 4850 X2 512MB, which has a GPU core clock speed of 625 MHz, and 512 MB of GDDR3 RAM running at 993 MHz through a 256-bit bus. It also features 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 4850 X2 512MB should be a lot faster than the GeForce 9800 GTX+ in general. (explain)
Texel RateThe Radeon HD 4850 X2 512MB is just a bit (about 6%) better at AF than the GeForce 9800 GTX+. (explain)
Pixel RateIf using a high screen resolution is important to you, then the Radeon HD 4850 X2 512MB is the winner, by far. (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: Bandwidth is the max amount of data (counted in MB per second) that can be transferred past the external memory interface in a second. It is calculated by multiplying the card's interface width by its memory clock speed. In the case of DDR type memory, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed per second. This is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The higher this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the most pixels the video card can possibly write to the local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.