Compare any two graphics cards:
Radeon HD 6790 vs Radeon HD 7950
IntroThe Radeon HD 6790 features a GPU core 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 features 800 Stream Processors, 40 TAUs, and 16 Raster Operation Units.
Compare those specifications to the Radeon HD 7950, which has GPU core speed of 800 MHz, and 1536 MB of GDDR5 memory set to run at 1250 MHz through a 384-bit bus. It also is made up of 1792 Stream Processors, 112 TAUs, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
As far as performance goes, the Radeon HD 7950 should theoretically be much superior to the Radeon HD 6790 overall. (explain)
Texel RateThe Radeon HD 7950 should be quite a bit (approximately 167%) more effective at anisotropic filtering than the Radeon HD 6790. (explain)
Pixel RateThe Radeon HD 7950 will be much (about 90%) better at FSAA than the Radeon HD 6790, and also able to handle higher resolutions without losing too much performance. (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 megabytes per second) that can be moved over the external memory interface in a second. It's worked out by multiplying the card's interface width by its memory clock speed. If the card has DDR type RAM, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied per second. This figure is calculated by multiplying the total texture units of the card by the core clock speed of the chip. The better the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly record to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.