Compare any two graphics cards:
Radeon HD 5870 vs Radeon HD 6950
IntroThe Radeon HD 5870 comes with a GPU core clock speed of 850 MHz, and the 1024 MB of GDDR5 RAM is set to run at 1200 MHz through a 256-bit bus. It also is made up of 1600(320x5) SPUs, 80 TAUs, and 32 ROPs.
Compare all that to the Radeon HD 6950, which uses a 40 nm design. AMD has set the core speed at 800 MHz. The GDDR5 memory runs at a speed of 1250 MHz on this specific card. It features 1408 SPUs along with 88 Texture Address Units and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 6950 should in theory be a small bit faster than the Radeon HD 5870 overall. (explain)
Texel RateThe Radeon HD 6950 should be a small bit (about 4%) better at anisotropic filtering than the Radeon HD 5870. (explain)
Pixel RateIf using a high resolution is important to you, then the Radeon HD 5870 is the winner, but not 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 max amount of information (measured in megabytes per second) that can be moved past the external memory interface in a second. It's calculated by multiplying the bus width by its memory speed. If the card has DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied per second. This figure is calculated 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 texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.
Pixel Rate: Pixel rate is the most pixels that the graphics chip could possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.