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 runs at 1000 MHz through a 256-bit bus. It also features 1600 SPUs, 160 TAUs, and 64 ROPs.
Compare all that to the Radeon HD 7870, which features 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 is made up of 1280 SPUs, 80 Texture Address Units, 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 theoretically be a lot superior to the Radeon HD 7870 in general. (explain)
Texel RateThe Radeon HD 5970 should be much (about 190%) better at AF than the Radeon HD 7870. (explain)
Pixel RateThe Radeon HD 5970 is much (more or less 190%) more effective at FSAA than the Radeon HD 7870, and capable of handling higher resolutions without slowing down too much. (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 (measured in MB per second) that can be transferred over the external memory interface in a second. It's calculated by multiplying the card's interface width by the speed of its memory. If the card has DDR type memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied in one second. This number is worked out by multiplying the total number of texture units by the core clock speed of the chip. The higher the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly write to its local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - aka 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 - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.