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 Rasterization Operator Units.
Compare all that to the Radeon HD 7950, which makes use of a 28 nm design. AMD has set 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.
Theoretically, the Radeon HD 7950 should be much faster than the Radeon HD 6950 overall. (explain)
Texel RateThe Radeon HD 7950 will be a lot (about 27%) better at anisotropic filtering than the Radeon HD 6950. (explain)
Pixel RateBoth cards have exactly the same pixel fill rate, so in theory they should perform 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 maximum amount of information (in units of megabytes per second) that can be transported past the external memory interface in one second. It's calculated by multiplying the bus width by its memory speed. If it uses DDR type memory, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better the card will be in general. It especially helps with AA, 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 figure is calculated by multiplying the total texture units by the core clock speed of the chip. The higher the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the most pixels that the graphics card can possibly record to its local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.