Compare any two graphics cards:
Radeon HD 5850 vs Radeon HD 7970
IntroThe Radeon HD 5850 has 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 is made up of 1440(288x5) Stream Processors, 72 Texture Address Units, and 32 ROPs.
Compare all of that to the Radeon HD 7970, which features clock speeds of 925 MHz on the GPU, and 1375 MHz on the 3072 MB of GDDR5 memory. It features 2048 SPUs along with 128 TAUs and 32 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 7970 should in theory be quite a bit faster than the Radeon HD 5850 overall. (explain)
Texel RateThe Radeon HD 7970 should be quite a bit (approximately 127%) more effective at anisotropic filtering than the Radeon HD 5850. (explain)
Pixel RateIf using a high screen resolution is important to you, then the Radeon HD 7970 is superior to the Radeon HD 5850, 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.
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 (in units of megabytes per second) that can be transported across the external memory interface in a second. It is calculated by multiplying the card's bus width by its memory clock speed. In the case of DDR RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better 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 are processed per second. This is worked out by multiplying the total number of texture units of the card by the core speed of the chip. The higher the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly record 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 the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.