Compare any two graphics cards:
Radeon HD 6950 vs Radeon HD 7950
IntroThe Radeon HD 6950 features clock speeds of 800 MHz on the GPU, and 1250 MHz on the 1024 MB of GDDR5 RAM. It features 1408 SPUs along with 88 Texture Address Units and 32 ROPs.
Compare all of that to the Radeon HD 7950, which makes use of a 28 nm design. AMD has clocked the core frequency at 800 MHz. The GDDR5 memory runs at a speed of 1250 MHz on this card. It features 1792 SPUs along with 112 TAUs 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 perform a lot faster than the Radeon HD 6950 in general. (explain)
Texel RateThe Radeon HD 7950 should be quite a bit (more or less 27%) faster with regards to anisotropic filtering than the Radeon HD 6950. (explain)
Pixel RateBoth cards have exactly the same pixel fill rate, so in theory they should be equally good at at full screen anti-aliasing, and be capable of handling 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 largest amount of data (in units of megabytes per second) that can be transferred across the external memory interface in a second. The number is worked out by multiplying the card's interface width by the speed of its memory. If it uses DDR RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed in one second. This number is calculated by multiplying the total number of texture units by the core clock speed of the chip. The higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.
Pixel Rate: Pixel rate is the most pixels the video card could possibly write to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.