Compare any two graphics cards:
GeForce 8600 GT 512MB DDR2 vs Radeon HD 5450
IntroThe GeForce 8600 GT 512MB DDR2 has clock speeds of 540 MHz on the GPU, and 400 MHz on the 512 MB of DDR2 RAM. It features 32 SPUs along with 16 Texture Address Units and 8 ROPs.
Compare all that to the Radeon HD 5450, which makes use of a 40 nm design. AMD has set the core frequency at 650 MHz. The DDR3 RAM runs at a frequency of 800 MHz on this specific card. It features 80(16x5) SPUs as well as 8 Texture Address Units and 4 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Both cards have exactly the same memory bandwidth, so theoretically they should have identical performance. (explain)
Texel RateThe GeForce 8600 GT 512MB DDR2 is much (approximately 66%) better at AF than the Radeon HD 5450. (explain)
Pixel RateIf running with a high screen resolution is important to you, then the GeForce 8600 GT 512MB DDR2 is the winner, 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 information (in units of megabytes per second) that can be transferred past the external memory interface in one second. It's worked out by multiplying the bus width by its memory speed. If it uses DDR RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better 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 per second. This is calculated by multiplying the total number 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 handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly write to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out 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 output rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.