Compare any two graphics cards:
Radeon HD 7850 vs Radeon HD 7970
IntroThe Radeon HD 7850 comes with a core clock speed of 860 MHz and a GDDR5 memory speed of 1200 MHz. It also makes use of a 256-bit memory bus, and makes use of a 28 nm design. It is made up of 1024 SPUs, 64 Texture Address Units, and 32 Raster Operation Units.
Compare those specs to the Radeon HD 7970, which has a clock speed of 925 MHz and a GDDR5 memory frequency of 1375 MHz. It also makes use of a 384-bit bus, and uses a 28 nm design. It is comprised of 2048 SPUs, 128 TAUs, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
As far as performance goes, the Radeon HD 7970 should in theory be a lot superior to the Radeon HD 7850 overall. (explain)
Texel RateThe Radeon HD 7970 is a lot (approximately 115%) more effective at anisotropic filtering than the Radeon HD 7850. (explain)
Pixel RateIf running with high levels of AA is important to you, then the Radeon HD 7970 is the winner, not by a very large margin though. (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 maximum amount of information (counted in megabytes per second) that can be transported past the external memory interface within a second. It is calculated by multiplying the card's bus width by the speed of its memory. If it uses DDR memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed in one second. This number is worked out by multiplying the total amount of texture units by the core 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 in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly write to its local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Render Output Units by the clock speed of the card. 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 rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.