Compare any two graphics cards:
Radeon HD 6790 vs Radeon HD 7790
IntroThe Radeon HD 6790 has a GPU clock speed of 840 MHz, and the 1024 MB of GDDR5 memory is set to run at 1050 MHz through a 256-bit bus. It also is made up of 800 Stream Processors, 40 TAUs, and 16 Raster Operation Units.
Compare those specs to the Radeon HD 7790, which comes with a clock speed of 1000 MHz and a GDDR5 memory speed of 1500 MHz. It also features a 128-bit bus, and makes use of a 28 nm design. It features 896 SPUs, 56 Texture Address Units, and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 6790 will be 40% faster than the Radeon HD 7790 overall, because of its greater bandwidth. (explain)
Texel RateThe Radeon HD 7790 is quite a bit (approximately 67%) more effective at anisotropic filtering than the Radeon HD 6790. (explain)
Pixel RateThe Radeon HD 7790 will be a small bit (about 19%) more effective at FSAA than the Radeon HD 6790, and also will be able to handle higher resolutions better. (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 (in units of MB per second) that can be transported over the external memory interface within a second. It's worked out by multiplying the card's bus width by its memory speed. If the card has DDR type memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed in one second. This is worked out by multiplying the total number of texture units by the core clock speed of the chip. The better this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.
Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly record to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the amount of colour ROPs by the clock 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 rate also depends on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.