Compare any two graphics cards:
GeForce 8500 GT vs Radeon HD 5450
IntroThe GeForce 8500 GT has a GPU core speed of 450 MHz, and the 512 MB of DDR2 memory is set to run at 400 MHz through a 128-bit bus. It also is made up of 16 SPUs, 8 Texture Address Units, and 4 ROPs.
Compare all that to the Radeon HD 5450, which has GPU clock speed of 650 MHz, and 512 MB of DDR3 RAM running at 800 MHz through a 64-bit bus. It also features 80(16x5) Stream Processors, 8 TAUs, and 4 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Both cards have exactly the same bandwidth, so in theory they should have the same performance. (explain)
Texel RateThe Radeon HD 5450 should be much (approximately 44%) more effective at AF than the GeForce 8500 GT. (explain)
Pixel RateThe Radeon HD 5450 is much (approximately 44%) better at full screen anti-aliasing than the GeForce 8500 GT, and will be capable of handling higher screen resolutions better. (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 maximum amount of information (in units of megabytes per second) that can be transported across the external memory interface in a second. It's calculated by multiplying the card's bus width by the speed of its memory. In the case of DDR type memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied per second. This figure is calculated by multiplying the total amount of texture units by the core speed of the chip. The higher the texel rate, the better the 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 number of pixels that the graphics chip can possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Render Output Units 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 quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.