Compare any two graphics cards:
Radeon HD 5970 vs Radeon HD 7870
IntroThe Radeon HD 5970 features a GPU clock speed of 725 MHz, and the 1024 MB of GDDR5 memory is set to run at 1000 MHz through a 256-bit bus. It also is made up of 1600 Stream Processors, 160 Texture Address Units, and 64 Raster Operation Units.
Compare those specifications to the Radeon HD 7870, which comes with GPU core speed of 1000 MHz, and 2048 MB of GDDR5 memory 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.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically, the Radeon HD 5970 should be much faster than the Radeon HD 7870 overall. (explain)
Texel RateThe Radeon HD 5970 is much (approximately 190%) more effective at anisotropic filtering than the Radeon HD 7870. (explain)
Pixel RateThe Radeon HD 5970 will be a lot (approximately 190%) faster with regards to AA than the Radeon HD 7870, and also capable of handling higher screen resolutions better. (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.
One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.
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 max amount of information (in units of megabytes per second) that can be transported across the external memory interface within a second. The number is worked out by multiplying the bus width by its memory clock speed. If it uses DDR 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 AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed in one second. This is calculated by multiplying the total number of texture units by the core speed of the chip. The better this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.
Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly write to its local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.