Compare any two graphics cards:
Radeon HD 7870 vs Radeon HD 7950 3GB
IntroThe Radeon HD 7870 features core speeds of 1000 MHz on the GPU, and 1200 MHz on the 2048 MB of GDDR5 RAM. It features 1280 SPUs along with 80 Texture Address Units and 32 ROPs.
Compare that to the Radeon HD 7950 3GB, which has a GPU core clock speed of 800 MHz, and 3072 MB of GDDR5 memory set to run at 1250 MHz through a 384-bit bus. It also is made up of 1792 SPUs, 112 TAUs, and 32 Raster Operation Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 7950 3GB should be 56% faster than the Radeon HD 7870 in general, because of its higher data rate. (explain)
Texel RateThe Radeon HD 7950 3GB will be a little bit (more or less 12%) more effective at AF than the Radeon HD 7870. (explain)
Pixel RateIf running with a high screen resolution is important to you, then the Radeon HD 7870 is the winner, by a large margin. (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 maximum amount of information (counted in MB per second) that can be transported across the external memory interface within a second. It is worked out by multiplying the card's interface width by its memory clock speed. If it uses DDR RAM, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. 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 number of texture map elements (texels) that are processed in one second. This number is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The higher this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly write to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of Raster Operations Pipelines 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 output rate is also dependant on many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.