Compare any two graphics cards:
GeForce GTX 580 vs Radeon HD 7870
IntroThe GeForce GTX 580 comes with a GPU clock speed of 772 MHz, and the 1536 MB of GDDR5 memory is set to run at 1002 MHz through a 384-bit bus. It also is comprised of 512 SPUs, 64 Texture Address Units, and 48 ROPs.
Compare all that to the Radeon HD 7870, which makes use of a 28 nm design. AMD has set the core speed at 1000 MHz. The GDDR5 RAM runs at a speed of 1200 MHz on this specific model. It features 1280 SPUs as well as 80 Texture Address Units and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the GeForce GTX 580 will be 25% quicker than the Radeon HD 7870 in general, due to its greater bandwidth. (explain)
Texel RateThe Radeon HD 7870 is quite a bit (more or less 62%) better at anisotropic filtering than the GeForce GTX 580. (explain)
Pixel RateIf using a high screen resolution is important to you, then the GeForce GTX 580 is a better choice, but only just. (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 data (in units of MB per second) that can be moved across the external memory interface in one second. It's calculated by multiplying the interface width by its memory speed. If it uses DDR type memory, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the memory bandwidth, 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 are applied in one second. This number is worked out by multiplying the total amount of texture units by the core speed of the chip. The higher the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.
Pixel Rate: Pixel rate is the most pixels the video card can possibly record to its local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.