Compare any two graphics cards:
Radeon HD 5870 vs Radeon HD 7770
IntroThe Radeon HD 5870 has a GPU core speed of 850 MHz, and the 1024 MB of GDDR5 memory is set to run at 1200 MHz through a 256-bit bus. It also is comprised of 1600(320x5) Stream Processors, 80 TAUs, and 32 ROPs.
Compare those specifications to the Radeon HD 7770, which has core clock speeds of 1000 MHz on the GPU, and 1125 MHz on the 1024 MB of GDDR5 memory. It features 640 SPUs along with 40 TAUs and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 5870 will be 113% quicker than the Radeon HD 7770 in general, due to its higher data rate. (explain)
Texel RateThe Radeon HD 5870 should be a lot (about 70%) faster with regards to anisotropic filtering than the Radeon HD 7770. (explain)
Pixel RateIf running with high levels of AA is important to you, then the Radeon HD 5870 is superior to the Radeon HD 7770, 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 (in units of MB per second) that can be transported across the external memory interface in a second. It is calculated by multiplying the card's interface width by its memory clock speed. If it uses DDR RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the 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 number of texture map elements (texels) that can be processed per second. This is calculated 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 per second.
Pixel Rate: Pixel rate is the most pixels the video card can possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.