Compare any two graphics cards:
Radeon HD 6770 vs Radeon HD 7770
IntroThe Radeon HD 6770 comes with core clock speeds of 900 MHz on the GPU, and 1050 MHz on the 512 MB of GDDR5 memory. It features 800 SPUs along with 40 Texture Address Units and 16 ROPs.
Compare all of that to the Radeon HD 7770, which comes with core clock speeds of 1000 MHz on the GPU, and 1125 MHz on the 1024 MB of GDDR5 RAM. It features 640 SPUs along with 40 TAUs and 16 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 7770 will be 7% quicker than the Radeon HD 6770 overall, because of its greater data rate. (explain)
Texel RateThe Radeon HD 7770 will be a bit (more or less 11%) more effective at AF than the Radeon HD 6770. (explain)
Pixel RateThe Radeon HD 7770 will be a small bit (about 11%) more effective at AA than the Radeon HD 6770, and should be able to handle higher 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: Memory bandwidth is the largest amount of information (counted in megabytes per second) that can be transferred across the external memory interface in a second. It's worked out by multiplying the bus width by its memory speed. If it uses DDR RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed in one second. This number is worked out by multiplying the total amount of texture units of the card by the core speed of the chip. The better this number, the better the graphics 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 amount of pixels that the graphics card can possibly write to the local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.