Compare any two graphics cards:
Radeon HD 5850 vs Radeon HD 7970
IntroThe Radeon HD 5850 comes with a GPU core speed of 725 MHz, and the 1024 MB of GDDR5 memory runs at 1000 MHz through a 256-bit bus. It also features 1440(288x5) SPUs, 72 TAUs, and 32 Raster Operation Units.
Compare that to the Radeon HD 7970, which has a clock frequency of 925 MHz and a GDDR5 memory frequency of 1375 MHz. It also makes use of a 384-bit memory bus, and makes use of a 28 nm design. It is comprised of 2048 SPUs, 128 Texture Address Units, and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically, the Radeon HD 7970 should perform much faster than the Radeon HD 5850 in general. (explain)
Texel RateThe Radeon HD 7970 is a lot (more or less 127%) more effective at anisotropic filtering than the Radeon HD 5850. (explain)
Pixel RateIf using a high screen resolution is important to you, then the Radeon HD 7970 is a better choice, by a large margin. (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 (measured in megabytes per second) that can be transferred across the external memory interface in a second. It is worked out by multiplying the interface width by the speed of its memory. If it uses DDR RAM, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied in one second. This number is worked out by multiplying the total number of texture units by the core clock speed of the chip. The better the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly record to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.