Compare any two graphics cards:
Radeon HD 5870 vs Radeon R9 280X
IntroThe Radeon HD 5870 has a GPU clock speed of 850 MHz, and the 1024 MB of GDDR5 RAM runs at 1200 MHz through a 256-bit bus. It also is comprised of 1600(320x5) SPUs, 80 Texture Address Units, and 32 ROPs.
Compare all that to the Radeon R9 280X, which has GPU core speed of 850 MHz, and 3072 MB of GDDR5 RAM set to run at 1500 MHz through a 384-bit bus. It also features 2048 SPUs, 128 TAUs, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
As far as performance goes, the Radeon R9 280X should in theory be much better than the Radeon HD 5870 overall. (explain)
Texel RateThe Radeon R9 280X should be much (approximately 60%) more effective at texture filtering than the Radeon HD 5870. (explain)
Pixel RateBoth cards have the exact same pixel fill rate, so theoretically they should perform equally good at at FSAA, and be able to handle the same screen 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 max amount of information (counted in MB per second) that can be transported past the external memory interface in a second. It's worked out by multiplying the bus width by its memory speed. In the case of DDR RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's 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 number of texture map elements (texels) that can be applied per second. This is worked out by multiplying the total texture units by the core speed of the chip. The better this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the most pixels that the graphics card can possibly write to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate also depends on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.