Compare any two graphics cards:
Radeon HD 5770 vs Radeon HD 5870
IntroThe Radeon HD 5770 features a GPU core clock speed of 850 MHz, and the 1024 MB of GDDR5 memory is set to run at 1200 MHz through a 128-bit bus. It also features 800(160x5) Stream Processors, 40 TAUs, and 16 Raster Operation Units.
Compare all that to the Radeon HD 5870, which makes use of a 40 nm design. AMD has clocked the core frequency at 850 MHz. The GDDR5 memory runs at a speed of 1200 MHz on this model. It features 1600(320x5) SPUs along with 80 Texture Address Units and 32 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 5870 is 100% faster than the Radeon HD 5770 in general, because of its greater bandwidth. (explain)
Texel RateThe Radeon HD 5870 is quite a bit (more or less 100%) more effective at anisotropic filtering than the Radeon HD 5770. (explain)
Pixel RateIf running with high levels of AA is important to you, then the Radeon HD 5870 is the winner, 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 largest amount of information (counted in MB per second) that can be transported across the external memory interface in a second. It's calculated by multiplying the interface width by its memory speed. If it uses DDR type memory, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed per second. This figure is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher the texel rate, 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 most pixels that the graphics chip can possibly record to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.