Compare any two graphics cards:
Radeon HD 5870 vs Radeon HD 6950
IntroThe Radeon HD 5870 has a GPU clock speed of 850 MHz, and the 1024 MB of GDDR5 memory runs at 1200 MHz through a 256-bit bus. It also is made up of 1600(320x5) SPUs, 80 Texture Address Units, and 32 Raster Operation Units.
Compare those specs to the Radeon HD 6950, which comes with a clock frequency of 800 MHz and a GDDR5 memory frequency of 1250 MHz. It also features a 256-bit memory bus, and uses a 40 nm design. It is comprised of 1408 SPUs, 88 TAUs, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 6950 should be a small bit faster than the Radeon HD 5870 overall. (explain)
Texel RateThe Radeon HD 6950 should be a small bit (approximately 4%) more effective at anisotropic filtering than the Radeon HD 5870. (explain)
Pixel RateThe Radeon HD 5870 is a small bit (more or less 6%) better at full screen anti-aliasing than the Radeon HD 6950, and also capable of handling higher screen resolutions without slowing down too much. (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.
Radeon HD 5870
Radeon HD 6950
Memory Bandwidth: Memory bandwidth is the max amount of information (counted in MB per second) that can be moved past the external memory interface in a second. It is calculated by multiplying the card's interface width by its memory clock speed. If the card has DDR type memory, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed per second. This number 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 applied in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip can possibly record to the local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number of Render Output Units by the the card's 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 rate also depends on lots of 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.
Radeon HD 5870
Radeon HD 6950