Compare any two graphics cards:
Radeon HD 7870 vs Radeon HD 7950
IntroThe Radeon HD 7870 has a GPU core clock speed of 1000 MHz, and the 2048 MB of GDDR5 memory is set to run at 1200 MHz through a 256-bit bus. It also features 1280 SPUs, 80 Texture Address Units, and 32 Raster Operation Units.
Compare all of that to the Radeon HD 7950, which comes with a clock frequency of 800 MHz and a GDDR5 memory speed of 1250 MHz. It also features a 384-bit memory bus, and makes use of a 28 nm design. It is made up of 1792 SPUs, 112 TAUs, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
As far as performance goes, the Radeon HD 7950 should in theory be much superior to the Radeon HD 7870 overall. (explain)
Texel RateThe Radeon HD 7950 will be a little bit (about 12%) more effective at anisotropic filtering than the Radeon HD 7870. (explain)
Pixel RateThe Radeon HD 7870 will be much (more or less 25%) better at AA than the Radeon HD 7950, and also should be capable of handling higher screen resolutions while still performing well. (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 megabytes per second) that can be transported across the external memory interface in a second. It's calculated by multiplying the interface width by its memory clock speed. In the case of DDR type RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, 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 texture map elements (texels) that are applied in one second. This figure is calculated by multiplying the total amount of texture units by the core speed of the chip. The higher this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the most pixels that the graphics card could possibly write to the local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the number of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.