Compare any two graphics cards:
Radeon HD 7950 vs Radeon HD 7970
IntroThe Radeon HD 7950 makes use of a 28 nm design. AMD has set the core frequency at 800 MHz. The GDDR5 RAM is set to run at a speed of 1250 MHz on this card. It features 1792 SPUs along with 112 Texture Address Units and 32 ROPs.
Compare that to the Radeon HD 7970, which has clock speeds of 925 MHz on the GPU, and 1375 MHz on the 3072 MB of GDDR5 RAM. It features 2048 SPUs as well as 128 Texture Address Units and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 7970 should be 10% quicker than the Radeon HD 7950 overall, because of its greater bandwidth. (explain)
Texel RateThe Radeon HD 7970 will be a lot (about 32%) better at texture filtering than the Radeon HD 7950. (explain)
Pixel RateIf running with a high screen resolution is important to you, then the Radeon HD 7970 is the winner, though 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: Bandwidth is the largest amount of data (in units of MB per second) that can be transferred past the external memory interface within a second. It is calculated by multiplying the card's bus width by its memory clock speed. In the case of DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. 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 amount of texture map elements (texels) that are applied per second. This is worked out by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly write to the local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the number of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.