Compare any two graphics cards:
Radeon HD 4770 vs Radeon HD 6770 1GB
IntroThe Radeon HD 4770 makes use of a 40 nm design. AMD has set the core frequency at 750 MHz. The GDDR5 memory runs at a speed of 800 MHz on this specific model. It features 640(128x5) SPUs as well as 32 TAUs and 16 Rasterization Operator Units.
Compare those specifications to the Radeon HD 6770 1GB, which has core speeds of 900 MHz on the GPU, and 1050 MHz on the 1024 MB of GDDR5 RAM. It features 800 SPUs as well as 40 TAUs and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 6770 1GB should be a lot faster than the Radeon HD 4770 in general. (explain)
Texel RateThe Radeon HD 6770 1GB should be quite a bit (approximately 50%) more effective at texture filtering than the Radeon HD 4770. (explain)
Pixel RateThe Radeon HD 6770 1GB should be just a bit (about 20%) better at FSAA than the Radeon HD 4770, and also will be capable of handling higher screen resolutions while still performing well. (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.
Memory Bandwidth: Memory bandwidth is the max amount of data (in units of MB per second) that can be transferred over the external memory interface in a second. It's calculated by multiplying the card's interface width by its memory speed. In the case of DDR memory, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed in one second. This number is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The higher this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly record to its local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number of ROPs by the the core speed of the card. 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 - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.