Compare any two graphics cards:
GeForce 9800 GTX vs Radeon HD 4830 512MB
IntroThe GeForce 9800 GTX features a clock speed of 675 MHz and a GDDR3 memory speed of 1100 MHz. It also makes use of a 256-bit bus, and makes use of a 65 nm design. It is made up of 128 SPUs, 64 Texture Address Units, and 16 Raster Operation Units.
Compare that to the Radeon HD 4830 512MB, which makes use of a 55 nm design. AMD has set the core speed at 575 MHz. The GDDR3 RAM works at a frequency of 900 MHz on this particular card. It features 640(128x5) SPUs as well as 32 Texture Address Units and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the GeForce 9800 GTX is 22% faster than the Radeon HD 4830 512MB overall, due to its greater bandwidth. (explain)
Texel RateThe GeForce 9800 GTX is quite a bit (about 135%) more effective at texture filtering than the Radeon HD 4830 512MB. (explain)
Pixel RateIf using a high screen resolution is important to you, then the GeForce 9800 GTX is superior to the Radeon HD 4830 512MB, 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: Bandwidth is the max amount of data (counted in MB per second) that can be transported across the external memory interface within a second. It is calculated by multiplying the card's bus width by its memory speed. In the case of DDR memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, 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 are applied in one second. This is calculated by multiplying the total texture units by the core 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 processed in a second.
Pixel Rate: Pixel rate is the maximum number of pixels the graphics card could possibly write to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.