Compare any two graphics cards:
Radeon HD 7770 vs Radeon HD 7870
IntroThe Radeon HD 7770 features a GPU clock speed of 1000 MHz, and the 1024 MB of GDDR5 memory is set to run at 1125 MHz through a 128-bit bus. It also is made up of 640 Stream Processors, 40 TAUs, and 16 Raster Operation Units.
Compare all that to the Radeon HD 7870, which makes use of a 28 nm design. AMD has set the core speed at 1000 MHz. The GDDR5 RAM works at a speed of 1200 MHz on this particular card. It features 1280 SPUs along with 80 TAUs and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the Radeon HD 7870 should theoretically be a lot superior to the Radeon HD 7770 overall. (explain)
Texel RateThe Radeon HD 7870 is quite a bit (about 100%) better at anisotropic filtering than the Radeon HD 7770. (explain)
Pixel RateThe Radeon HD 7870 will be much (about 100%) better at full screen anti-aliasing than the Radeon HD 7770, and also will be able to handle higher resolutions more effectively. (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 largest amount of information (measured in megabytes per second) that can be transferred over the external memory interface in one second. The number is calculated by multiplying the card's interface width by its memory speed. In the case of DDR type memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, 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 texture map elements (texels) that are applied per second. This figure is calculated by multiplying the total number of texture units by the core speed of the chip. The better this number, the better the 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 maximum number of pixels the video card could possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number 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 drawing the pixels (image) on the screen. The actual pixel fill rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.