Compare any two graphics cards:
Radeon HD 6970 vs Radeon HD 7870
IntroThe Radeon HD 6970 features a core clock speed of 880 MHz and a GDDR5 memory frequency of 1375 MHz. It also makes use of a 256-bit memory bus, and makes use of a 40 nm design. It is made up of 1536 SPUs, 96 Texture Address Units, and 32 Raster Operation Units.
Compare all that to the Radeon HD 7870, which features a GPU core clock speed of 1000 MHz, and 2048 MB of GDDR5 RAM set to run at 1200 MHz through a 256-bit bus. It also is made up of 1280 Stream Processors, 80 Texture Address Units, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 6970 should be 15% quicker than the Radeon HD 7870 in general, due to its greater data rate. (explain)
Texel RateThe Radeon HD 6970 will be a bit (more or less 6%) better at texture filtering than the Radeon HD 7870. (explain)
Pixel RateIf running with a high screen resolution is important to you, then the Radeon HD 7870 is superior to the Radeon HD 6970, 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: Bandwidth is the largest amount of information (counted in MB per second) that can be transported past the external memory interface in a second. The number is calculated by multiplying the interface width by its memory clock speed. If the card has DDR type RAM, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster 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 can be applied in one second. This is worked out by multiplying the total texture units by the core clock speed of the chip. The better the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.
Pixel Rate: Pixel rate is the most pixels the video card could possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called 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, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.