Compare any two graphics cards:
GeForce 8500 GT vs Radeon HD 5450
IntroThe GeForce 8500 GT features a GPU clock 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 Stream Processors, 8 TAUs, and 4 Raster Operation Units.
Compare those specs to the Radeon HD 5450, which comes with GPU clock speed of 650 MHz, and 512 MB of DDR3 RAM set to run at 800 MHz through a 64-bit bus. It also is made up of 80(16x5) SPUs, 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 quite a bit (about 44%) faster with regards to texture filtering than the GeForce 8500 GT. (explain)
Pixel RateThe Radeon HD 5450 should be much (approximately 44%) more effective at full screen anti-aliasing than the GeForce 8500 GT, and also should be capable of handling higher screen resolutions more effectively. (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 (counted in megabytes per second) that can be moved across the external memory interface in one second. It's calculated by multiplying the interface width by its memory speed. If the card has DDR type RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the 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 texture map elements (texels) that are processed in one second. This is worked out by multiplying the total amount of texture units of the card by the core clock speed of the chip. The better the texel rate, the better the graphics 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 graphics card could possibly write to the local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the amount 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 outputting the pixels (image) to the screen. The actual pixel rate also depends on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.