Compare any two graphics cards:
Radeon HD 6950 vs Radeon HD 7950
IntroThe Radeon HD 6950 uses a 40 nm design. AMD has set the core speed at 800 MHz. The GDDR5 RAM is set to run at a frequency of 1250 MHz on this model. It features 1408 SPUs along with 88 TAUs and 32 ROPs.
Compare those specifications to the Radeon HD 7950, which uses a 28 nm design. AMD has clocked the core speed at 800 MHz. The GDDR5 memory runs at a frequency of 1250 MHz on this specific model. It features 1792 SPUs along with 112 Texture Address Units and 32 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
In theory, the Radeon HD 7950 should be 50% faster than the Radeon HD 6950 in general, because of its greater bandwidth. (explain)
Texel RateThe Radeon HD 7950 should be a lot (approximately 27%) more effective at AF than the Radeon HD 6950. (explain)
Pixel RateBoth cards have the exact same pixel fill rate, so in theory they should be equally good at at AA, 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: Memory bandwidth is the maximum amount of data (in units of MB per second) that can be transported across the external memory interface in one second. It's worked out by multiplying the interface width by its memory speed. If it uses DDR type RAM, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the card's 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 texture map elements (texels) that can be processed in one second. This is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The higher this number, the better the video 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 most pixels the graphics card can possibly write to its local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Render Output Units by the the card's clock speed. 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 output rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.