Compare any two graphics cards:
Radeon HD 7870 vs Radeon HD 7950 3GB
IntroThe Radeon HD 7870 has clock speeds of 1000 MHz on the GPU, and 1200 MHz on the 2048 MB of GDDR5 memory. It features 1280 SPUs as well as 80 Texture Address Units and 32 Rasterization Operator Units.
Compare that to the Radeon HD 7950 3GB, which has a GPU core clock speed of 800 MHz, and 3072 MB of GDDR5 memory set to run at 1250 MHz through a 384-bit bus. It also is made up of 1792 Stream Processors, 112 TAUs, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
As far as performance goes, the Radeon HD 7950 3GB should in theory be quite a bit better than the Radeon HD 7870 in general. (explain)
Texel RateThe Radeon HD 7950 3GB should be a bit (more or less 12%) better at texture filtering than the Radeon HD 7870. (explain)
Pixel RateIf using a high screen resolution is important to you, then the Radeon HD 7870 is the winner, 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 data (in units of megabytes per second) that can be transferred across the external memory interface within a second. The number is worked out by multiplying the bus width by its memory speed. In the case of DDR memory, the result 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 anti-aliasing, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied per second. This is worked out by multiplying the total texture units by the core clock 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 processed in a second.
Pixel Rate: Pixel rate is the most pixels the video card could possibly record to its local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the amount of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.