Compare any two graphics cards:
Radeon HD 6950 vs Radeon HD 7870
IntroThe Radeon HD 6950 has a GPU core clock speed of 800 MHz, and the 1024 MB of GDDR5 RAM is set to run at 1250 MHz through a 256-bit bus. It also is made up of 1408 Stream Processors, 88 Texture Address Units, and 32 Raster Operation Units.
Compare those specs to the Radeon HD 7870, which features core clock speeds of 1000 MHz on the GPU, and 1200 MHz on the 2048 MB of GDDR5 memory. It features 1280 SPUs as well as 80 TAUs and 32 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically, the Radeon HD 6950 should be a bit faster than the Radeon HD 7870 overall. (explain)
Texel RateThe Radeon HD 7870 should be a bit (more or less 14%) more effective at texture filtering than the Radeon HD 6950. (explain)
Pixel RateIf using a high resolution is important to you, then the Radeon HD 7870 is a better choice, by a large margin. (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 (in units of MB per second) that can be transported over the external memory interface in a second. The number is calculated by multiplying the interface width by the speed of its memory. If it uses DDR type RAM, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed per second. This is worked out by multiplying the total number 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 processed in a second.
Pixel Rate: Pixel rate is the maximum number of pixels the graphics card could possibly write to its local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate is also dependant on many 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.