Compare any two graphics cards:
GeForce 8400 GS 512MB vs Radeon HD 5450
IntroThe GeForce 8400 GS 512MB uses a 80 nm design. nVidia has clocked the core frequency at 650 MHz. The DDR2 RAM works at a frequency of 400 MHz on this particular card. It features 16 SPUs as well as 8 Texture Address Units and 4 Rasterization Operator Units.
Compare all that to the Radeon HD 5450, which makes use of a 40 nm design. AMD has clocked the core frequency at 650 MHz. The DDR3 memory works at a speed of 800 MHz on this card. It features 80(16x5) SPUs along with 8 Texture Address Units and 4 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 5450 should be quite a bit faster than the GeForce 8400 GS 512MB overall. (explain)
Texel RateBoth cards have the exact same texel rate, so in theory they should be equally good at at AF. (explain)
Pixel RateBoth cards have exactly the same pixel rate, so in theory they should be equally good at at full screen anti-aliasing, and be able to handle the same screen resolutions. (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 largest amount of information (in units of megabytes per second) that can be transported across the external memory interface within a second. It's worked out by multiplying the interface width by its memory speed. If the card has DDR memory, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed per second. This figure is calculated by multiplying the total texture units of the card by the core clock speed of the chip. The higher this number, the better the 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 amount of pixels that the graphics card could possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of colour ROPs by the the core speed of the card. 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 many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.