Compare any two graphics cards:
Radeon HD 6950 vs Radeon HD 7870
IntroThe Radeon HD 6950 has clock speeds of 800 MHz on the GPU, and 1250 MHz on the 1024 MB of GDDR5 memory. It features 1408 SPUs as well as 88 Texture Address Units and 32 Rasterization Operator Units.
Compare that to the Radeon HD 7870, which comes with a clock speed of 1000 MHz and a GDDR5 memory speed of 1200 MHz. It also makes use of a 256-bit memory bus, and uses a 28 nm design. It is comprised of 1280 SPUs, 80 Texture Address Units, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 6950 is 4% faster than the Radeon HD 7870 overall, because of its higher data rate. (explain)
Texel RateThe Radeon HD 7870 will be just a bit (approximately 14%) faster with regards to AF than the Radeon HD 6950. (explain)
Pixel RateIf using a high resolution is important to you, then the Radeon HD 7870 is superior to the Radeon HD 6950, by far. (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 megabytes per second) that can be transported over the external memory interface within a second. The number is worked out by multiplying the interface width by its memory clock speed. In the case of DDR type RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This is calculated by multiplying the total texture units of the card by the core clock speed of the chip. The better the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.
Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly record to its 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 the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.