Compare any two graphics cards:
GeForce 9500 GT DDR2 vs Radeon HD 5450
IntroThe GeForce 9500 GT DDR2 features core clock speeds of 550 MHz on the GPU, and 500 MHz on the 256 MB of DDR2 memory. It features 32 SPUs as well as 16 Texture Address Units and 8 ROPs.
Compare those specifications to the Radeon HD 5450, which comes with GPU core speed of 650 MHz, and 512 MB of DDR3 memory running at 800 MHz through a 64-bit bus. It also is comprised of 80(16x5) SPUs, 8 TAUs, and 4 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the GeForce 9500 GT DDR2 will be 25% quicker than the Radeon HD 5450 overall, because of its higher bandwidth. (explain)
Texel RateThe GeForce 9500 GT DDR2 will be much (more or less 69%) faster with regards to texture filtering than the Radeon HD 5450. (explain)
Pixel RateThe GeForce 9500 GT DDR2 is a lot (about 69%) better at anti-aliasing than the Radeon HD 5450, and will be able to handle 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.
Memory Bandwidth: Memory bandwidth is the max amount of data (in units of MB per second) that can be transported past the external memory interface within a second. It is worked out by multiplying the bus width by its memory clock speed. In the case of DDR type RAM, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range 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 texture units of the card by the core clock speed of the chip. The higher this number, 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 amount of pixels that the graphics card could possibly record to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number 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 rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.