Compare any two graphics cards:
Radeon HD 6950 2GB vs Radeon HD 7950 3GB
IntroThe Radeon HD 6950 2GB makes use of a 40 nm design. AMD has set the core speed at 800 MHz. The GDDR5 RAM works at a frequency of 1250 MHz on this particular model. It features 1408 SPUs as well as 88 TAUs and 32 ROPs.
Compare those specifications to the Radeon HD 7950 3GB, which has core clock speeds of 800 MHz on the GPU, and 1250 MHz on the 3072 MB of GDDR5 memory. It features 1792 SPUs as well as 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 3GB should be quite a bit 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 AF than the Radeon HD 6950 2GB. (explain)
Pixel RateBoth cards have the exact same pixel rate, so in theory they should perform equally good at at full screen anti-aliasing, and be able to handle 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 largest amount of data (measured in MB per second) that can be transported across the external memory interface in a second. It's calculated by multiplying the interface width by its memory clock speed. If it uses DDR RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed in one second. This number is worked out by multiplying the total number of texture units of the card by the core 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 applied per second.
Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly record to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.