Compare any two graphics cards:
GeForce GTX 580 vs Radeon HD 7850
IntroThe GeForce GTX 580 comes with a GPU core clock 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 comprised of 512 Stream Processors, 64 TAUs, and 48 Raster Operation Units.
Compare those specs to the Radeon HD 7850, which uses a 28 nm design. AMD has set the core speed at 860 MHz. The GDDR5 memory works at a speed of 1200 MHz on this particular model. It features 1024 SPUs as well as 64 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 25% quicker than the Radeon HD 7850 overall, because of its higher bandwidth. (explain)
Texel RateThe Radeon HD 7850 should be just a bit (approximately 11%) faster with regards to AF than the GeForce GTX 580. (explain)
Pixel RateIf running with high levels of AA is important to you, then the GeForce GTX 580 is a better choice, and very much so. (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 (measured in MB per second) that can be transferred over the external memory interface in one second. It is worked out by multiplying the bus width by its memory speed. If it uses DDR memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied per second. This is calculated by multiplying the total amount of 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 in a second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly record to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount 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 fill rate also depends on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.