Compare any two graphics cards:
GeForce 9800 GT 512MB vs Radeon HD 4830 512MB
IntroThe GeForce 9800 GT 512MB comes with a clock frequency of 600 MHz and a GDDR3 memory speed of 900 MHz. It also makes use of a 256-bit memory bus, and makes use of a 65/55 nm design. It is comprised of 112 SPUs, 56 TAUs, and 16 ROPs.
Compare all that to the Radeon HD 4830 512MB, which features core speeds of 575 MHz on the GPU, and 900 MHz on the 512 MB of GDDR3 RAM. It features 640(128x5) SPUs along with 32 TAUs and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Both cards have the exact same bandwidth, so theoretically they should perform the same. (explain)
Texel RateThe GeForce 9800 GT 512MB will be quite a bit (more or less 83%) more effective at texture filtering than the Radeon HD 4830 512MB. (explain)
Pixel RateIf using lots of anti-aliasing is important to you, then the GeForce 9800 GT 512MB is the winner, but it probably won't make a huge difference. (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 information (counted in megabytes per second) that can be transported across the external memory interface in one second. It's calculated by multiplying the interface width by its memory clock speed. If the card has DDR type memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better 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 processed per second. This number is worked out by multiplying the total number of texture units by the core clock speed of the chip. The better the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.
Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly record to the local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Render Output Units by the the core 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 fill rate also depends on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.