Compare any two graphics cards:
Radeon HD 7770 vs Radeon HD 7850
IntroThe Radeon HD 7770 features 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 Texture Address Units and 16 Rasterization Operator Units.
Compare that to the Radeon HD 7850, which makes use of a 28 nm design. AMD has clocked the core frequency at 860 MHz. The GDDR5 RAM is set to run at a frequency of 1200 MHz on this particular model. It features 1024 SPUs along with 64 TAUs and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 7850, in theory, should be quite a bit faster than the Radeon HD 7770 in general. (explain)
Texel RateThe Radeon HD 7850 will be much (about 38%) faster with regards to texture filtering than the Radeon HD 7770. (explain)
Pixel RateIf using a high screen resolution is important to you, then the Radeon HD 7850 is a better choice, by a large margin. (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 maximum amount of data (in units of megabytes per second) that can be transferred past the external memory interface in a second. It's calculated by multiplying the interface width by the speed of its memory. In the case of DDR type RAM, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied per second. This is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The better this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly write to its local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.