Compare any two graphics cards:
Radeon HD 7770 vs Radeon HD 7870
IntroThe Radeon HD 7770 uses a 28 nm design. AMD has clocked the core speed at 1000 MHz. The GDDR5 RAM runs at a frequency of 1125 MHz on this model. It features 640 SPUs as well as 40 TAUs and 16 Rasterization Operator Units.
Compare all that to the Radeon HD 7870, which comes with GPU clock speed of 1000 MHz, and 2048 MB of GDDR5 RAM running at 1200 MHz through a 256-bit bus. It also is comprised of 1280 SPUs, 80 Texture Address Units, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the Radeon HD 7870 should theoretically be quite a bit better than the Radeon HD 7770 in general. (explain)
Texel RateThe Radeon HD 7870 is much (approximately 100%) better at anisotropic filtering than the Radeon HD 7770. (explain)
Pixel RateIf running with lots of anti-aliasing is important to you, then the Radeon HD 7870 is a better choice, by a large margin. (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: Bandwidth is the max amount of data (counted in megabytes per second) that can be transferred past the external memory interface within a second. The number is worked out by multiplying the card's bus width by the speed of its memory. In the case of DDR RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied in one second. This figure is worked out by multiplying the total texture units by the core speed of the chip. The better the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.
Pixel Rate: Pixel rate is the most pixels the graphics card could possibly write to its local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called 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, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.