Compare any two graphics cards:
Radeon HD 6950 2GB vs Radeon HD 7950 3GB
IntroThe Radeon HD 6950 2GB comes with a GPU clock speed of 800 MHz, and the 2048 MB of GDDR5 RAM runs at 1250 MHz through a 256-bit bus. It also features 1408 Stream Processors, 88 TAUs, and 32 ROPs.
Compare that to the Radeon HD 7950 3GB, which features a core clock speed of 800 MHz and a GDDR5 memory frequency of 1250 MHz. It also features a 384-bit memory bus, and uses a 28 nm design. It features 1792 SPUs, 112 TAUs, and 32 Raster Operation Units.
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
The Radeon HD 7950 3GB, in theory, should perform much faster than the Radeon HD 6950 2GB in general. (explain)
Texel RateThe Radeon HD 7950 3GB will be much (about 27%) faster with regards to anisotropic filtering than the Radeon HD 6950 2GB. (explain)
Pixel RateBoth cards have exactly the same pixel rate, so in theory they should be equally good at at FSAA, and be able to handle the same resolutions. (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 information (counted in MB per second) that can be transported past the external memory interface within a second. It's calculated by multiplying the card's interface width by its memory clock speed. If the card has DDR type RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed per second. This figure is calculated by multiplying the total amount of texture units of the card by the core clock speed of the chip. The better this number, the better the graphics card will be at 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 write to the local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.