Compare any two graphics cards:
GeForce GTX 580 vs Radeon HD 7870
IntroThe GeForce GTX 580 has core speeds of 772 MHz on the GPU, and 1002 MHz on the 1536 MB of GDDR5 RAM. It features 512 SPUs as well as 64 TAUs and 48 ROPs.
Compare those specifications to the Radeon HD 7870, which has core clock speeds of 1000 MHz on the GPU, and 1200 MHz on the 2048 MB of GDDR5 RAM. It features 1280 SPUs along with 80 Texture Address Units and 32 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the GeForce GTX 580 should be a lot faster than the Radeon HD 7870 overall. (explain)
Texel RateThe Radeon HD 7870 will be much (approximately 62%) more effective at AF than the GeForce GTX 580. (explain)
Pixel RateThe GeForce GTX 580 is just a bit (about 16%) more effective at anti-aliasing than the Radeon HD 7870, and also able to handle higher screen resolutions without losing too much performance. (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 information (counted in megabytes per second) that can be moved across the external memory interface within a second. The number is calculated by multiplying the card's bus width by the speed of its memory. If it uses DDR type RAM, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed per second. This figure is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The higher this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the most pixels the video card could possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount 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 output rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.