Compare any two graphics cards:
Radeon HD 6950 2GB vs Radeon HD 7950 3GB
IntroThe Radeon HD 6950 2GB uses a 40 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 model. It features 1408 SPUs along with 88 Texture Address Units and 32 Rasterization Operator Units.
Compare those specifications to the Radeon HD 7950 3GB, which makes use of a 28 nm design. AMD has set the core speed at 800 MHz. The GDDR5 RAM works at a speed of 1250 MHz on this specific card. It features 1792 SPUs along with 112 TAUs and 32 ROPs.
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
In theory, the Radeon HD 7950 3GB should be 50% quicker than the Radeon HD 6950 2GB in general, because of its higher data rate. (explain)
Texel RateThe Radeon HD 7950 3GB should be much (about 27%) better at AF than the Radeon HD 6950 2GB. (explain)
Pixel RateBoth cards have exactly the same pixel rate, so theoretically they should perform equally good at at full screen anti-aliasing, and be capable of handling the same screen 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 (in units of megabytes per second) that can be moved over the external memory interface within a second. It's worked out by multiplying the interface width by the speed of its memory. If the card has DDR type RAM, the result should 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 AA, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed per second. This figure is calculated by multiplying the total texture units by the core clock speed of the chip. The higher this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.