Compare any two graphics cards:
Radeon HD 5870 vs Radeon HD 7950
IntroThe Radeon HD 5870 features a GPU clock speed of 850 MHz, and the 1024 MB of GDDR5 RAM runs at 1200 MHz through a 256-bit bus. It also is made up of 1600(320x5) Stream Processors, 80 TAUs, and 32 ROPs.
Compare all of that to the Radeon HD 7950, which features clock speeds of 800 MHz on the GPU, and 1250 MHz on the 1536 MB of GDDR5 RAM. It features 1792 SPUs as well as 112 Texture Address Units and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 7950, in theory, should perform quite a bit faster than the Radeon HD 5870 in general. (explain)
Texel RateThe Radeon HD 7950 is a lot (more or less 32%) faster with regards to anisotropic filtering than the Radeon HD 5870. (explain)
Pixel RateIf using a high screen resolution is important to you, then the Radeon HD 5870 is the winner, but it probably won't make a huge difference. (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: Bandwidth is the largest amount of information (measured in megabytes per second) that can be moved across the external memory interface in a second. The number is worked out by multiplying the interface width by the speed of its memory. If the card has DDR RAM, the result should be multiplied by 2 again. If it uses 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 amount of texture map elements (texels) that are applied per second. This figure is worked out by multiplying the total number of texture units of the card by the core speed of the chip. The higher the texel rate, the better the graphics card will be at handling 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 could possibly write to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.