Compare any two graphics cards:
Radeon HD 6970 vs Radeon HD 7870
IntroThe Radeon HD 6970 has core speeds of 880 MHz on the GPU, and 1375 MHz on the 2048 MB of GDDR5 RAM. It features 1536 SPUs as well as 96 Texture Address Units and 32 ROPs.
Compare that to the Radeon HD 7870, which has a clock speed of 1000 MHz and a GDDR5 memory frequency of 1200 MHz. It also uses a 256-bit memory bus, and makes use of a 28 nm design. It is made up of 1280 SPUs, 80 TAUs, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 6970 should in theory perform just a bit faster than the Radeon HD 7870 in general. (explain)
Texel RateThe Radeon HD 6970 will be a bit (about 6%) more effective at anisotropic filtering than the Radeon HD 7870. (explain)
Pixel RateIf using lots of anti-aliasing is important to you, then the Radeon HD 7870 is a better choice, not by a very large margin though. (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 MB per second) that can be transferred across the external memory interface in one second. It's calculated by multiplying the card's bus width by the speed of its memory. If the card has DDR RAM, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better 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 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 video 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 maximum amount of pixels that the graphics card could possibly record to the local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.