Compare any two graphics cards:
GeForce 8600 GT 512MB DDR2 vs Radeon HD 5450
IntroThe GeForce 8600 GT 512MB DDR2 features a GPU clock speed of 540 MHz, and the 512 MB of DDR2 memory runs at 400 MHz through a 128-bit bus. It also is comprised of 32 SPUs, 16 Texture Address Units, and 8 ROPs.
Compare all that to the Radeon HD 5450, which comes with a clock speed of 650 MHz and a DDR3 memory speed of 800 MHz. It also uses a 64-bit memory bus, and uses a 40 nm design. It is comprised of 80(16x5) SPUs, 8 TAUs, and 4 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Both cards have exactly the same memory bandwidth, so in theory they should perform exactly the same. (explain)
Texel RateThe GeForce 8600 GT 512MB DDR2 should be much (approximately 66%) better at AF than the Radeon HD 5450. (explain)
Pixel RateIf using lots of anti-aliasing is important to you, then the GeForce 8600 GT 512MB DDR2 is the winner, 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 maximum amount of information (measured in MB per second) that can be moved over the external memory interface within a second. It's worked out by multiplying the interface width by its memory clock speed. If the card has DDR RAM, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied in one second. This figure is calculated by multiplying the total amount of texture units of the card by the core speed of the chip. The higher this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could 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 Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.