Compare any two graphics cards:
GeForce 8400 GS 512MB vs Radeon HD 5450
IntroThe GeForce 8400 GS 512MB features clock speeds of 650 MHz on the GPU, and 400 MHz on the 512 MB of DDR2 RAM. It features 16 SPUs along with 8 Texture Address Units and 4 ROPs.
Compare those specs to the Radeon HD 5450, which has GPU clock speed of 650 MHz, and 512 MB of DDR3 memory running at 800 MHz through a 64-bit bus. It also is made up of 80(16x5) Stream Processors, 8 Texture Address Units, and 4 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 5450 will be 100% quicker than the GeForce 8400 GS 512MB in general, because of its higher data rate. (explain)
Texel RateBoth cards have exactly the same texel fill rate, so in theory they should perform equally good at at anisotropic filtering. (explain)
Pixel RateBoth cards have exactly the same pixel rate, so in theory they should perform equally good at at FSAA, and be capable of handling 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: Memory bandwidth is the maximum amount of information (counted in megabytes per second) that can be moved past the external memory interface in one second. It is worked out by multiplying the interface width by its memory clock speed. In the case of DDR memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, 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 worked out 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 card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.
Pixel Rate: Pixel rate is the maximum number of pixels the video card could possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.