Compare any two graphics cards:
Radeon HD 5870 vs Radeon HD 7970
IntroThe Radeon HD 5870 has a clock speed of 850 MHz and a GDDR5 memory frequency of 1200 MHz. It also makes use of a 256-bit memory bus, and uses a 40 nm design. It is comprised of 1600(320x5) SPUs, 80 Texture Address Units, and 32 Raster Operation Units.
Compare all of that to the Radeon HD 7970, which features clock speeds of 925 MHz on the GPU, and 1375 MHz on the 3072 MB of GDDR5 memory. It features 2048 SPUs along with 128 TAUs and 32 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the Radeon HD 7970 should theoretically be quite a bit superior to the Radeon HD 5870 in general. (explain)
Texel RateThe Radeon HD 7970 will be much (more or less 74%) better at AF than the Radeon HD 5870. (explain)
Pixel RateIf running with lots of anti-aliasing is important to you, then the Radeon HD 7970 is superior to the Radeon HD 5870, 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 data (in units of MB per second) that can be moved past the external memory interface in one second. It's calculated by multiplying the card's bus width by its memory clock speed. In the case of DDR type memory, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed in one second. This number is worked out by multiplying the total texture units of the card by the core speed of the chip. The better this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly record to the local memory per second - measured in millions of pixels per second. Pixel rate is worked out 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 rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.