Compare any two graphics cards:
Radeon HD 7850 vs Radeon HD 7970
IntroThe Radeon HD 7850 comes with core speeds of 860 MHz on the GPU, and 1200 MHz on the 2048 MB of GDDR5 RAM. It features 1024 SPUs along with 64 Texture Address Units and 32 ROPs.
Compare all 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 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 7970, in theory, should be quite a bit faster than the Radeon HD 7850 in general. (explain)
Texel RateThe Radeon HD 7970 will be a lot (more or less 115%) better at anisotropic filtering than the Radeon HD 7850. (explain)
Pixel RateIf running with a high screen resolution is important to you, then the Radeon HD 7970 is the winner, though not 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 max amount of information (in units of MB per second) that can be transported across the external memory interface in a second. It's calculated by multiplying the card's bus width by its memory clock speed. In the case of DDR type RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied per second. This number is calculated by multiplying the total texture units of the card by the core speed of the chip. The better the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the maximum number of 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 number of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.