Compare any two graphics cards:
Radeon HD 6770 vs Radeon HD 7770
IntroThe Radeon HD 6770 uses a 40 nm design. AMD has set the core speed at 900 MHz. The GDDR5 RAM works at a frequency of 1050 MHz on this card. It features 800 SPUs along with 40 Texture Address Units and 16 Rasterization Operator Units.
Compare those specifications to the Radeon HD 7770, which comes with clock speeds of 1000 MHz on the GPU, and 1125 MHz on the 1024 MB of GDDR5 RAM. It features 640 SPUs as well as 40 TAUs and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 7770 should perform just a bit faster than the Radeon HD 6770 overall. (explain)
Texel RateThe Radeon HD 7770 will be just a bit (approximately 11%) faster with regards to AF than the Radeon HD 6770. (explain)
Pixel RateIf using a high resolution is important to you, then the Radeon HD 7770 is the winner, but only just. (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 maximum amount of data (measured in megabytes per second) that can be moved across the external memory interface within a second. The number is worked out by multiplying the card's interface width by the speed of its memory. If it uses DDR RAM, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed per second. This figure is worked out by multiplying the total number of texture units by the core clock speed of the chip. The higher this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly record to its local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the amount of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.