Compare any two graphics cards:
Radeon HD 5870 vs Radeon R9 280X
IntroThe Radeon HD 5870 has a GPU core speed of 850 MHz, and the 1024 MB of GDDR5 memory is set to run at 1200 MHz through a 256-bit bus. It also is comprised of 1600(320x5) Stream Processors, 80 Texture Address Units, and 32 Raster Operation Units.
Compare that to the Radeon R9 280X, which comes with a core clock frequency of 850 MHz and a GDDR5 memory speed of 1500 MHz. It also uses a 384-bit bus, and makes use of a 28 nm design. It is comprised of 2048 SPUs, 128 TAUs, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon R9 280X should in theory be a lot faster than the Radeon HD 5870 in general. (explain)
Texel RateThe Radeon R9 280X will be quite a bit (approximately 60%) more effective at texture filtering than the Radeon HD 5870. (explain)
Pixel RateBoth cards have exactly the same pixel fill rate, so in theory they should be equally good at at AA, and be capable of handling the same resolutions. (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 megabytes per second) that can be transported across the external memory interface within a second. The number is worked out by multiplying the card's interface width by its memory speed. If the card has DDR type memory, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the better the card will be in general. It especially helps with AA, 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 number of texture units by the core clock speed of the chip. The better this number, the better the video 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 the video card can possibly write to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the amount of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.