Compare any two graphics cards:
Radeon HD 5770 vs Radeon HD 7850
IntroThe Radeon HD 5770 comes with a GPU clock speed of 850 MHz, and the 1024 MB of GDDR5 memory runs at 1200 MHz through a 128-bit bus. It also is made up of 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.
Compare that to the Radeon HD 7850, which comes with a GPU core clock speed of 860 MHz, and 2048 MB of GDDR5 RAM set to run at 1200 MHz through a 256-bit bus. It also is made up of 1024 SPUs, 64 TAUs, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
As far as performance goes, the Radeon HD 7850 should in theory be much better than the Radeon HD 5770 overall. (explain)
Texel RateThe Radeon HD 7850 should be much (about 62%) more effective at anisotropic filtering than the Radeon HD 5770. (explain)
Pixel RateIf using a high screen resolution is important to you, then the Radeon HD 7850 is superior to the Radeon HD 5770, and very much so. (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 (counted in MB per second) that can be transferred past the external memory interface within a second. The number is worked out by multiplying the card's bus width by the speed of its memory. If the card has DDR type RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the better the card will be in general. It especially helps with AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This is worked out by multiplying the total amount of texture units by the core speed of the chip. The better the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly write to the local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also 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.