Compare any two graphics cards:
Radeon HD 7870 vs Radeon HD 7950
IntroThe Radeon HD 7870 has a clock speed of 1000 MHz and a GDDR5 memory frequency of 1200 MHz. It also features a 256-bit memory bus, and uses a 28 nm design. It is comprised of 1280 SPUs, 80 TAUs, and 32 Raster Operation Units.
Compare those specs to the Radeon HD 7950, which uses a 28 nm design. AMD has clocked the core speed at 800 MHz. The GDDR5 memory works at a frequency of 1250 MHz on this model. It features 1792 SPUs along with 112 TAUs and 32 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 7950, in theory, should be a lot faster than the Radeon HD 7870 in general. (explain)
Texel RateThe Radeon HD 7950 will be a little bit (more or less 12%) faster with regards to anisotropic filtering than the Radeon HD 7870. (explain)
Pixel RateThe Radeon HD 7870 should be quite a bit (about 25%) better at AA than the Radeon HD 7950, and also will be able to handle higher 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 7870
Radeon HD 7950
Memory Bandwidth: Bandwidth is the max amount of data (in units of MB per second) that can be transferred past the external memory interface within a second. The number is calculated by multiplying the bus width by its memory clock speed. If it uses 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 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 texture map elements (texels) that can be applied per second. This number is worked out by multiplying the total number of texture units of the card by the core speed of the chip. The higher this number, the better the 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 the video card could possibly record to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of colour ROPs 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 output rate is also dependant on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.
Radeon HD 7870
Radeon HD 7950