Compare any two graphics cards:
GeForce 8400 GS 512MB vs Radeon HD 5450
IntroThe GeForce 8400 GS 512MB comes with a core clock frequency of 650 MHz and a DDR2 memory frequency of 400 MHz. It also makes use of a 64-bit memory bus, and uses a 80 nm design. It is made up of 16 SPUs, 8 TAUs, and 4 ROPs.
Compare those specs to the Radeon HD 5450, which comes with GPU clock 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 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 5450 should be a lot faster than the GeForce 8400 GS 512MB overall. (explain)
Texel RateBoth cards have exactly the same texel rate, so theoretically they should be equally good at at AF. (explain)
Pixel RateBoth cards have the exact same pixel rate, so in theory they should perform 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 largest amount of data (measured in MB per second) that can be transferred past the external memory interface within a second. It's calculated by multiplying the card's interface width by its memory speed. In the case of DDR memory, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed per second. This figure is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly write to its local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the amount of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.