Compare any two graphics cards:
GeForce GTX 580 vs Radeon HD 7870
IntroThe GeForce GTX 580 features core clock speeds of 772 MHz on the GPU, and 1002 MHz on the 1536 MB of GDDR5 RAM. It features 512 SPUs along with 64 TAUs and 48 Rasterization Operator Units.
Compare that to the Radeon HD 7870, which makes use of a 28 nm design. AMD has clocked the core speed at 1000 MHz. The GDDR5 memory is set to run at a frequency of 1200 MHz on this particular model. It features 1280 SPUs as well as 80 TAUs and 32 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
As far as performance goes, the GeForce GTX 580 should theoretically be much better than the Radeon HD 7870 overall. (explain)
Texel RateThe Radeon HD 7870 should be much (approximately 62%) faster with regards to texture filtering than the GeForce GTX 580. (explain)
Pixel RateIf using a high screen resolution is important to you, then the GeForce GTX 580 is the winner, not by a very large margin though. (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 max amount of data (in units of MB per second) that can be transferred past the external memory interface within a second. The number is worked out by multiplying the card's bus width by the speed of its memory. If the card has DDR RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied in one second. This is calculated by multiplying the total texture units by the core clock speed of the chip. The better the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.
Pixel Rate: Pixel rate is the most pixels the graphics card can possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.