Compare any two graphics cards:
Radeon HD 6970 vs Radeon HD 7950
IntroThe Radeon HD 6970 has a GPU clock speed of 880 MHz, and the 2048 MB of GDDR5 RAM runs at 1375 MHz through a 256-bit bus. It also is comprised of 1536 SPUs, 96 Texture Address Units, and 32 Raster Operation Units.
Compare that to the Radeon HD 7950, which comes with a core clock frequency of 800 MHz and a GDDR5 memory speed of 1250 MHz. It also uses a 384-bit memory bus, and uses a 28 nm design. It is comprised of 1792 SPUs, 112 Texture Address Units, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 7950 should be 36% faster than the Radeon HD 6970 in general, due to its greater data rate. (explain)
Texel RateThe Radeon HD 7950 should be a bit (more or less 6%) more effective at anisotropic filtering than the Radeon HD 6970. (explain)
Pixel RateThe Radeon HD 6970 will be just a bit (more or less 10%) more effective at AA than the Radeon HD 7950, and will be able to handle higher screen resolutions more effectively. (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 (counted in megabytes per second) that can be transferred across the external memory interface in one second. It's worked out by multiplying the card's interface width by its memory speed. In the case of DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the bandwidth is, the faster 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 number of texture map elements (texels) that are applied per second. This figure is worked out by multiplying the total number of texture units by the core clock speed of the chip. The better this number, 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 maximum amount of pixels that the graphics chip can possibly write to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the amount of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.