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 card. It features 1408 SPUs along with 88 TAUs and 32 Rasterization Operator Units.
Compare that to the Radeon HD 7950 3GB, which makes use of a 28 nm design. AMD has clocked the core frequency at 800 MHz. The GDDR5 RAM is set to run at a speed of 1250 MHz on this particular model. It features 1792 SPUs along with 112 Texture Address Units and 32 ROPs.
(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 perform a lot faster than the Radeon HD 6950 2GB in general. (explain)
Texel RateThe Radeon HD 7950 3GB will be much (about 27%) more effective at AF than the Radeon HD 6950 2GB. (explain)
Pixel RateBoth cards have exactly the same pixel fill rate, so theoretically they should be equally good at at AA, 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: Bandwidth is the max amount of information (in units of megabytes per second) that can be moved across the external memory interface in one second. The number is worked out by multiplying the interface width by the speed of its memory. If it uses DDR type memory, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better 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 applied per second. This number is calculated by multiplying the total texture units by the core clock speed of the chip. The higher this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly record to the local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.