Compare any two graphics cards:
GeForce 9800 GX2 vs Radeon HD 3870 1GB
IntroThe GeForce 9800 GX2 features clock speeds of 600 MHz on the GPU, and 1000 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 1GB, which features core speeds of 775 MHz on the GPU, and 1125 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
Power Consumption (Max TDP)
In theory, the GeForce 9800 GX2 will be 78% quicker than the Radeon HD 3870 1GB overall, due to its greater data rate. (explain)
Texel RateThe GeForce 9800 GX2 will be much (more or less 519%) faster with regards to AF than the Radeon HD 3870 1GB. (explain)
Pixel RateIf running with high levels of AA is important to you, then the GeForce 9800 GX2 is superior to the Radeon HD 3870 1GB, by a large margin. (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 maximum amount of information (measured in megabytes per second) that can be moved past the external memory interface within a second. It's worked out by multiplying the card's bus width by its memory clock speed. If the card has DDR type memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed in one second. This number is worked out by multiplying the total amount of texture units of the card by the core speed of the chip. The better this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the maximum number of pixels the video card could possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.