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 set the core frequency at 650 MHz. The DDR2 RAM runs at a frequency of 400 MHz on this particular model. It features 16 SPUs along with 8 TAUs and 4 Rasterization Operator Units.
Compare all that to the Radeon HD 5450, which has GPU core speed of 650 MHz, and 512 MB of DDR3 RAM running at 800 MHz through a 64-bit bus. It also is comprised of 80(16x5) SPUs, 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% faster than the GeForce 8400 GS 512MB in general, because of its greater data rate. (explain)
Texel RateBoth cards have exactly the same texel rate, so in theory they should perform equally good at at AF. (explain)
Pixel RateBoth cards have the exact same pixel rate, so in theory they should be equally good at at full screen anti-aliasing, and be able to handle the same 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 data (in units of MB per second) that can be transported over the external memory interface within a second. It's calculated by multiplying the interface width by its memory speed. If it uses DDR type RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, the faster the card will be in general. It especially helps with AA, High Dynamic Range 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 number of texture units by the core clock 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 in one second.
Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly write to the local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.