Compare any two graphics cards:
Radeon HD 4670 1GB vs Radeon HD 7770
IntroThe Radeon HD 4670 1GB uses a 55 nm design. AMD has clocked the core speed at 750 MHz. The GDDR4/GDDR3/DDR3/DDR2 memory is set to run at a frequency of 1100 MHz on this model. It features 320(64x5) SPUs along with 32 Texture Address Units and 8 Rasterization Operator Units.
Compare those specs to the Radeon HD 7770, which uses a 28 nm design. AMD has clocked the core frequency at 1000 MHz. The GDDR5 RAM is set to run at a frequency of 1125 MHz on this model. It features 640 SPUs as well as 40 TAUs and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 7770 should be 105% faster than the Radeon HD 4670 1GB overall, due to its higher bandwidth. (explain)
Texel RateThe Radeon HD 7770 is quite a bit (about 67%) better at AF than the Radeon HD 4670 1GB. (explain)
Pixel RateIf using lots of anti-aliasing is important to you, then the Radeon HD 7770 is a better choice, 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: Bandwidth is the largest amount of information (in units of megabytes per second) that can be transferred past the external memory interface in one second. The number is calculated by multiplying the card's interface width by its memory clock speed. If the card has DDR RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed per second. This 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 video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.
Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly write to the local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Raster Operations Pipelines by the the core speed of the card. 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 fill rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.