Compare any two graphics cards:
GeForce GTX 580 vs Radeon HD 7970
IntroThe GeForce GTX 580 has clock 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 Texture Address Units and 48 ROPs.
Compare those specs to the Radeon HD 7970, which uses a 28 nm design. AMD has clocked the core speed at 925 MHz. The GDDR5 memory runs at a frequency of 1375 MHz on this specific card. It features 2048 SPUs as well as 128 TAUs and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically, the Radeon HD 7970 should be a lot faster than the GeForce GTX 580 in general. (explain)
Texel RateThe Radeon HD 7970 is much (more or less 140%) more effective at texture filtering than the GeForce GTX 580. (explain)
Pixel RateIf using a high resolution is important to you, then the GeForce GTX 580 is the winner, by a large margin. (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 largest amount of data (measured in MB per second) that can be transported across the external memory interface within a second. The number is worked out by multiplying the card's bus width by its memory speed. If it uses DDR memory, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the better 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 can be processed per second. This is worked out by multiplying the total texture units of the card by the core speed of the chip. The better the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.
Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly write to its local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.