Compare any two graphics cards:
Radeon HD 6790 vs Radeon HD 7770
IntroThe Radeon HD 6790 makes use of a 40 nm design. AMD has set the core speed at 840 MHz. The GDDR5 memory works at a frequency of 1050 MHz on this particular card. It features 800 SPUs along with 40 TAUs and 16 Rasterization Operator Units.
Compare all that to the Radeon HD 7770, which features a clock speed of 1000 MHz and a GDDR5 memory speed of 1125 MHz. It also makes use of a 128-bit memory bus, and makes use of a 28 nm design. It features 640 SPUs, 40 Texture Address Units, and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 6790 should perform a lot faster than the Radeon HD 7770 overall. (explain)
Texel RateThe Radeon HD 7770 should be a little bit (more or less 19%) better at texture filtering than the Radeon HD 6790. (explain)
Pixel RateThe Radeon HD 7770 is a bit (about 19%) better at full screen anti-aliasing than the Radeon HD 6790, and should be capable of handling higher resolutions without slowing down too much. (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 maximum amount of data (measured in megabytes per second) that can be moved across the external memory interface within a second. It's calculated by multiplying the interface width by its memory speed. If it uses DDR RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This number is worked out by multiplying the total texture units of the card by the core speed of the chip. The higher the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly write to the local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called 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 of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.