Compare any two graphics cards:
GeForce GTX 580 vs Radeon HD 7870
IntroThe GeForce GTX 580 comes with a GPU core speed of 772 MHz, and the 1536 MB of GDDR5 RAM is set to run at 1002 MHz through a 384-bit bus. It also is made up of 512 Stream Processors, 64 Texture Address Units, and 48 ROPs.
Compare those specs to the Radeon HD 7870, which features GPU clock speed of 1000 MHz, and 2048 MB of GDDR5 memory set to run at 1200 MHz through a 256-bit bus. It also is comprised of 1280 Stream Processors, 80 TAUs, and 32 Raster Operation Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the GeForce GTX 580 will be 25% quicker than the Radeon HD 7870 overall, because of its higher bandwidth. (explain)
Texel RateThe Radeon HD 7870 will be a lot (more or less 62%) faster with regards to texture filtering than the GeForce GTX 580. (explain)
Pixel RateIf running with lots of anti-aliasing is important to you, then the GeForce GTX 580 is the winner, but not by far. (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: Memory bandwidth is the largest amount of data (counted in MB per second) that can be moved over the external memory interface within a second. It is calculated by multiplying the card's interface width by the speed of its memory. In the case of DDR type memory, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied per second. This is worked out by multiplying the total texture units by the core clock 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 most pixels the video card could possibly record to the local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the number of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on many 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.