Compare any two graphics cards:
Radeon HD 7850 vs Radeon HD 7970
IntroThe Radeon HD 7850 has a GPU clock speed of 860 MHz, and the 2048 MB of GDDR5 memory runs at 1200 MHz through a 256-bit bus. It also features 1024 Stream Processors, 64 TAUs, and 32 Raster Operation Units.
Compare those specifications to the Radeon HD 7970, which comes with a core clock speed of 925 MHz and a GDDR5 memory frequency of 1375 MHz. It also uses a 384-bit bus, and makes use of a 28 nm design. It features 2048 SPUs, 128 TAUs, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 7970 will be 72% quicker than the Radeon HD 7850 in general, due to its greater data rate. (explain)
Texel RateThe Radeon HD 7970 should be much (approximately 115%) more effective at AF than the Radeon HD 7850. (explain)
Pixel RateIf using a high resolution is important to you, then the Radeon HD 7970 is superior to the Radeon HD 7850, 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 maximum amount of information (in units of MB per second) that can be transported past the external memory interface in one second. The number is worked out by multiplying the bus width by its memory clock speed. If the card has DDR type RAM, the result 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, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied in one second. This is calculated by multiplying the total amount of texture units of the card by the core clock speed of the chip. The better the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly write to its local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of Raster Operations Pipelines 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 fill rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.