Compare any two graphics cards:
GeForce GT 420 vs Radeon HD 5450
IntroThe GeForce GT 420 comes with core clock speeds of 700 MHz on the GPU, and 900 MHz on the 2048 MB of GDDR3 RAM. It features 48 SPUs along with 8 Texture Address Units and 4 Rasterization Operator Units.
Compare those specifications to the Radeon HD 5450, which features a clock frequency of 650 MHz and a DDR3 memory speed of 800 MHz. It also uses a 64-bit memory bus, and uses a 40 nm design. It is made up of 80(16x5) SPUs, 8 Texture Address Units, and 4 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the GeForce GT 420 is 125% faster than the Radeon HD 5450 overall, due to its greater data rate. (explain)
Texel RateThe GeForce GT 420 should be a little bit (more or less 8%) more effective at AF than the Radeon HD 5450. (explain)
Pixel RateThe GeForce GT 420 should be a little bit (approximately 8%) faster with regards to full screen anti-aliasing than the Radeon HD 5450, and should be able to handle 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.
GeForce GT 420
Radeon HD 5450
Memory Bandwidth: Bandwidth is the max amount of information (in units of megabytes per second) that can be transferred over the external memory interface within a second. It's worked out by multiplying the card's bus width by its memory speed. If it uses DDR RAM, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster 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 are applied per second. This number is calculated by multiplying the total number of texture units by the core clock speed of the chip. The better the texel rate, the better the card will be at handling 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 chip could possibly write to its local memory per second - measured in millions of pixels per second. Pixel rate is worked out 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 filling the screen with pixels (the image). The actual pixel rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.
GeForce GT 420
Radeon HD 5450