Compare any two graphics cards:
Radeon HD 5870 vs Radeon HD 7950
IntroThe Radeon HD 5870 has a GPU core clock speed of 850 MHz, and the 1024 MB of GDDR5 memory is set to run at 1200 MHz through a 256-bit bus. It also features 1600(320x5) Stream Processors, 80 Texture Address Units, and 32 Raster Operation Units.
Compare those specs to the Radeon HD 7950, which has a clock frequency of 800 MHz and a GDDR5 memory speed of 1250 MHz. It also makes use of a 384-bit memory bus, and makes use of a 28 nm design. It features 1792 SPUs, 112 TAUs, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 7950 should perform much faster than the Radeon HD 5870 in general. (explain)
Texel RateThe Radeon HD 7950 will be a lot (about 32%) more effective at anisotropic filtering than the Radeon HD 5870. (explain)
Pixel RateThe Radeon HD 5870 will be just a bit (more or less 6%) more effective at anti-aliasing than the Radeon HD 7950, and also will be capable of handling higher resolutions while still performing well. (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 7950
Memory Bandwidth: Memory bandwidth is the largest amount of data (in units of megabytes per second) that can be moved across the external memory interface in one second. The number is calculated by multiplying the card's interface width by its memory speed. If the card has DDR memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This number is worked out by multiplying the total texture units by the core speed of the chip. The higher this number, the better the graphics 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 that the graphics card could possibly write to its local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the number of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.
Radeon HD 5870
Radeon HD 7950