Compare any two graphics cards:
Radeon HD 6870 vs Radeon HD 7770
IntroThe Radeon HD 6870 uses a 40 nm design. AMD has clocked the core frequency at 900 MHz. The GDDR5 memory runs at a speed of 1050 MHz on this card. It features 1120 SPUs along with 56 Texture Address Units and 32 ROPs.
Compare that to the Radeon HD 7770, which comes with core speeds of 1000 MHz on the GPU, and 1125 MHz on the 1024 MB of GDDR5 memory. It features 640 SPUs along with 40 TAUs and 16 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the Radeon HD 6870 should theoretically be much better than the Radeon HD 7770 overall. (explain)
Texel RateThe Radeon HD 6870 should be much (more or less 26%) more effective at AF than the Radeon HD 7770. (explain)
Pixel RateThe Radeon HD 6870 is much (approximately 80%) better at anti-aliasing than the Radeon HD 7770, and also will be able to handle higher screen resolutions better. (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 (in units of megabytes per second) that can be transferred over the external memory interface within a second. The number is calculated by multiplying the card's bus width by the speed of its memory. If the card has DDR type memory, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed per second. This figure is calculated by multiplying the total number of texture units by the core speed of the chip. The better the texel rate, the better the card will be at 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 can possibly write to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the amount of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.