Compare any two graphics cards:
Radeon HD 5970 vs Radeon HD 7870
IntroThe Radeon HD 5970 has clock speeds of 725 MHz on the GPU, and 1000 MHz on the 1024 MB of GDDR5 memory. It features 1600 SPUs along with 160 Texture Address Units and 64 ROPs.
Compare all of that to the Radeon HD 7870, which comes with core speeds of 1000 MHz on the GPU, and 1200 MHz on the 2048 MB of GDDR5 RAM. It features 1280 SPUs as well as 80 TAUs and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the Radeon HD 5970 should in theory be quite a bit better than the Radeon HD 7870 overall. (explain)
Texel RateThe Radeon HD 5970 will be a lot (about 190%) more effective at anisotropic filtering than the Radeon HD 7870. (explain)
Pixel RateIf using a high resolution is important to you, then the Radeon HD 5970 is the winner, by far. (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: Memory bandwidth is the largest amount of data (measured in MB per second) that can be transferred over the external memory interface within a second. It's calculated by multiplying the bus width by its memory clock speed. If it uses DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the bandwidth is, the better 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 can be processed in one second. This is worked out by multiplying the total amount of texture units by the core speed of the chip. The higher the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.