Compare any two graphics cards:
Radeon HD 5850 vs Radeon HD 7970
IntroThe Radeon HD 5850 features a GPU core speed of 725 MHz, and the 1024 MB of GDDR5 memory runs at 1000 MHz through a 256-bit bus. It also features 1440(288x5) SPUs, 72 Texture Address Units, and 32 Raster Operation Units.
Compare those specs to the Radeon HD 7970, which has clock speeds of 925 MHz on the GPU, and 1375 MHz on the 3072 MB of GDDR5 memory. It features 2048 SPUs as well as 128 TAUs and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 7970 is 106% faster than the Radeon HD 5850 in general, due to its higher bandwidth. (explain)
Texel RateThe Radeon HD 7970 will be a lot (more or less 127%) more effective at anisotropic filtering than the Radeon HD 5850. (explain)
Pixel RateIf running with high levels of AA is important to you, then the Radeon HD 7970 is the winner, 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.
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 data (in units of megabytes per second) that can be transferred past the external memory interface in a second. The number is worked out by multiplying the card's interface width by its memory speed. If the card has DDR type memory, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This number is worked out by multiplying the total number of texture units of the card by the core 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 per second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly record to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the amount 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, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.