Compare any two graphics cards:
Radeon HD 5870 vs Radeon HD 7970
IntroThe Radeon HD 5870 comes with a clock frequency of 850 MHz and a GDDR5 memory frequency of 1200 MHz. It also features a 256-bit memory bus, and makes use of a 40 nm design. It is comprised of 1600(320x5) SPUs, 80 TAUs, and 32 Raster Operation Units.
Compare that to the Radeon HD 7970, which comes with clock speeds of 925 MHz on the GPU, and 1375 MHz on the 3072 MB of GDDR5 memory. It features 2048 SPUs as well as 128 TAUs and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 7970 should be much faster than the Radeon HD 5870 overall. (explain)
Texel RateThe Radeon HD 7970 is a lot (about 74%) more effective at texture filtering than the Radeon HD 5870. (explain)
Pixel RateThe Radeon HD 7970 should be just a bit (about 9%) more effective at full screen anti-aliasing than the Radeon HD 5870, and also should be capable of handling higher screen resolutions while still performing well. (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: Memory bandwidth is the max amount of information (in units of MB per second) that can be moved across the external memory interface in one second. The number is worked out by multiplying the bus width by its memory speed. If the card has DDR RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied in one second. This number is calculated by multiplying the total amount of texture units by the core clock speed of the chip. The higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.
Pixel Rate: Pixel rate is the most pixels the graphics card could possibly record to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.