Compare any two graphics cards:
Radeon HD 6790 vs Radeon HD 7950
IntroThe Radeon HD 6790 has a GPU 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 is comprised of 800 SPUs, 40 TAUs, and 16 Raster Operation Units.
Compare all that to the Radeon HD 7950, which makes use of a 28 nm design. AMD has set the core speed at 800 MHz. The GDDR5 memory is set to run at a frequency of 1250 MHz on this specific card. It features 1792 SPUs as well as 112 Texture Address Units and 32 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 7950 should be 79% quicker than the Radeon HD 6790 in general, because of its greater data rate. (explain)
Texel RateThe Radeon HD 7950 should be a lot (approximately 167%) faster with regards to AF than the Radeon HD 6790. (explain)
Pixel RateThe Radeon HD 7950 should be much (approximately 90%) better at anti-aliasing than the Radeon HD 6790, and should be capable of handling higher screen 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 information (in units of megabytes per second) that can be transferred past the external memory interface in a second. It is worked out by multiplying the interface width by its memory speed. In the case of DDR type memory, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed per second. This is calculated by multiplying the total number of texture units 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 per second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly write to the local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the amount of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on many 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.