Compare any two graphics cards:
Radeon HD 5970 vs Radeon HD 7870
IntroThe Radeon HD 5970 features a GPU core 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 features 1600 Stream Processors, 160 TAUs, and 64 Raster Operation Units.
Compare those specifications to the Radeon HD 7870, which comes with core clock speeds of 1000 MHz on the GPU, and 1200 MHz on the 2048 MB of GDDR5 RAM. It features 1280 SPUs along with 80 TAUs and 32 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 5970 will be 67% quicker than the Radeon HD 7870 in general, because of its higher bandwidth. (explain)
Texel RateThe Radeon HD 5970 will be quite a bit (approximately 190%) more effective at anisotropic filtering than the Radeon HD 7870. (explain)
Pixel RateThe Radeon HD 5970 should be much (more or less 190%) better at anti-aliasing than the Radeon HD 7870, and should be capable of handling higher screen resolutions without losing too much performance. (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 information (in units of MB per second) that can be transferred across the external memory interface within a second. It's worked out by multiplying the card's interface width by the speed of its memory. In the case of DDR memory, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed in one second. This is worked out by multiplying the total amount of texture units of the card by the core speed of the chip. The better this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the maximum number of pixels the video card 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 Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.