Compare any two graphics cards:
Radeon HD 7770 vs Radeon HD 7870
IntroThe Radeon HD 7770 comes with a core clock speed of 1000 MHz and a GDDR5 memory frequency of 1125 MHz. It also makes use of a 128-bit bus, and makes use of a 28 nm design. It features 640 SPUs, 40 TAUs, and 16 Raster Operation Units.
Compare all of that to the Radeon HD 7870, which has a GPU core clock speed of 1000 MHz, and 2048 MB of GDDR5 RAM set to run at 1200 MHz through a 256-bit bus. It also features 1280 SPUs, 80 TAUs, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 7870 should be 113% quicker than the Radeon HD 7770 in general, due to its higher bandwidth. (explain)
Texel RateThe Radeon HD 7870 will be quite a bit (more or less 100%) better at anisotropic filtering than the Radeon HD 7770. (explain)
Pixel RateThe Radeon HD 7870 is a lot (more or less 100%) faster with regards to AA than the Radeon HD 7770, and also capable of handling higher screen 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.
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 max amount of data (measured in MB per second) that can be transferred past the external memory interface within a second. The number is calculated by multiplying the card's bus width by its memory speed. If it uses DDR type RAM, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better 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 amount of texture map elements (texels) that are processed per second. This figure is worked out by multiplying the total texture units by the core speed of the chip. The better this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly record to the local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.