Compare any two graphics cards:
Radeon HD 6770 vs Radeon HD 7770
IntroThe Radeon HD 6770 has clock speeds of 900 MHz on the GPU, and 1050 MHz on the 512 MB of GDDR5 RAM. It features 800 SPUs along with 40 TAUs and 16 Rasterization Operator Units.
Compare that to the Radeon HD 7770, which comes with GPU core speed of 1000 MHz, and 1024 MB of GDDR5 memory set to run at 1125 MHz through a 128-bit bus. It also features 640 SPUs, 40 Texture Address Units, and 16 Raster Operation Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 7770 will be 7% faster than the Radeon HD 6770 in general, due to its higher bandwidth. (explain)
Texel RateThe Radeon HD 7770 is a bit (more or less 11%) more effective at anisotropic filtering than the Radeon HD 6770. (explain)
Pixel RateIf running with a high resolution is important to you, then the Radeon HD 7770 is superior to the Radeon HD 6770, but not by far. (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 megabytes per second) that can be transferred past the external memory interface in a second. It is calculated by multiplying the interface width by its memory clock speed. If it uses DDR memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied in one second. This figure is calculated by multiplying the total amount of texture units of the card by the core clock speed of the chip. The higher this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly write to its local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the number of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.