Compare any two graphics cards:
Radeon HD 6950 vs Radeon HD 7870
IntroThe Radeon HD 6950 has a clock frequency of 800 MHz and a GDDR5 memory frequency of 1250 MHz. It also features a 256-bit memory bus, and makes use of a 40 nm design. It is made up of 1408 SPUs, 88 Texture Address Units, and 32 ROPs.
Compare that to the Radeon HD 7870, which has core speeds of 1000 MHz on the GPU, and 1200 MHz on the 2048 MB of GDDR5 RAM. It features 1280 SPUs as well as 80 TAUs and 32 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 6950 should be a bit faster than the Radeon HD 7870 overall. (explain)
Texel RateThe Radeon HD 7870 is just a bit (about 14%) more effective at anisotropic filtering than the Radeon HD 6950. (explain)
Pixel RateIf using lots of anti-aliasing is important to you, then the Radeon HD 7870 is the winner, 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 max amount of information (in units of MB per second) that can be moved across the external memory interface in one second. The number is worked out by multiplying the card's interface width by its memory clock speed. If it uses DDR type RAM, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed per second. This number is calculated by multiplying the total texture units by the core speed of the chip. The better the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the most pixels the video card can possibly record to the local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.