Compare any two graphics cards:
Radeon HD 5870 vs Radeon HD 7970
IntroThe Radeon HD 5870 features a clock frequency of 850 MHz and a GDDR5 memory speed of 1200 MHz. It also uses a 256-bit bus, and uses a 40 nm design. It is comprised of 1600(320x5) SPUs, 80 Texture Address Units, and 32 Raster Operation Units.
Compare those specifications to the Radeon HD 7970, which makes use of a 28 nm design. AMD has clocked the core frequency at 925 MHz. The GDDR5 memory works at a speed of 1375 MHz on this card. It features 2048 SPUs along with 128 TAUs and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 7970 is 72% quicker than the Radeon HD 5870 overall, due to its greater data rate. (explain)
Texel RateThe Radeon HD 7970 should be much (approximately 74%) faster with regards to AF than the Radeon HD 5870. (explain)
Pixel RateThe Radeon HD 7970 is just a bit (approximately 9%) better at anti-aliasing than the Radeon HD 5870, and capable of handling higher resolutions without slowing down too much. (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 data (counted in megabytes per second) that can be transported over the external memory interface in one second. The number is worked out by multiplying the bus width by the speed of its memory. In the case of DDR type memory, it must be multiplied by 2 again. If it uses 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, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed per second. This figure is worked out by multiplying the total number of texture units by the core speed of the chip. The higher this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly write to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.