Compare any two graphics cards:
Radeon HD 6790 vs Radeon HD 6870
IntroThe Radeon HD 6790 has a GPU core clock speed of 840 MHz, and the 1024 MB of GDDR5 RAM is set to run at 1050 MHz through a 256-bit bus. It also features 800 Stream Processors, 40 TAUs, and 16 ROPs.
Compare that to the Radeon HD 6870, which uses a 40 nm design. AMD has set the core speed at 900 MHz. The GDDR5 RAM is set to run at a speed of 1050 MHz on this model. It features 1120 SPUs as well as 56 Texture Address Units and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Both cards have the exact same bandwidth, so in theory they should have identical performance. (explain)
Texel RateThe Radeon HD 6870 is much (more or less 50%) more effective at texture filtering than the Radeon HD 6790. (explain)
Pixel RateThe Radeon HD 6870 will be much (approximately 114%) more effective at anti-aliasing than the Radeon HD 6790, and also will 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 max amount of data (measured in MB per second) that can be moved over the external memory interface in one second. It is calculated by multiplying the card's interface width by its memory clock speed. If the card has DDR memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount 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 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 in a second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly record to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.