Compare any two graphics cards:
Radeon HD 7850 vs Radeon HD 7970
IntroThe Radeon HD 7850 features a GPU clock speed of 860 MHz, and the 2048 MB of GDDR5 RAM runs at 1200 MHz through a 256-bit bus. It also is comprised of 1024 SPUs, 64 Texture Address Units, and 32 Raster Operation Units.
Compare that to the Radeon HD 7970, which comes with 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 Texture Address Units and 32 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
As far as performance goes, the Radeon HD 7970 should in theory be much better than the Radeon HD 7850 overall. (explain)
Texel RateThe Radeon HD 7970 will be a lot (about 115%) better at texture filtering than the Radeon HD 7850. (explain)
Pixel RateIf using a high resolution is important to you, then the Radeon HD 7970 is superior to the Radeon HD 7850, though only just barely. (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: Bandwidth is the largest amount of information (counted in MB per second) that can be moved over the external memory interface within a second. The number is worked out by multiplying the card's interface width by its memory clock speed. In the case of DDR memory, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This is calculated by multiplying the total amount of texture units by the core speed of the chip. The higher the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.
Pixel Rate: Pixel rate is the most pixels the video card could possibly record to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.