Compare any two graphics cards:
GeForce GT 420 vs Radeon HD 5450
IntroThe GeForce GT 420 features a clock frequency of 700 MHz and a GDDR3 memory speed of 900 MHz. It also features a 128-bit memory bus, and uses a 40 nm design. It is made up of 48 SPUs, 8 Texture Address Units, and 4 Raster Operation Units.
Compare those specifications to the Radeon HD 5450, which features clock speeds of 650 MHz on the GPU, and 800 MHz on the 512 MB of DDR3 RAM. It features 80(16x5) SPUs along with 8 Texture Address Units and 4 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The GeForce GT 420 should in theory be quite a bit faster than the Radeon HD 5450 in general. (explain)
Texel RateThe GeForce GT 420 is a small bit (approximately 8%) better at anisotropic filtering than the Radeon HD 5450. (explain)
Pixel RateThe GeForce GT 420 will be a bit (more or less 8%) faster with regards to FSAA than the Radeon HD 5450, and also should be able to handle higher screen resolutions while still performing well. (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: Memory bandwidth is the max amount of information (counted in megabytes per second) that can be moved across the external memory interface in one second. It's worked out by multiplying the card's interface width by its memory speed. If the card has DDR RAM, it should be multiplied by 2 once 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, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed in one second. This is worked out by multiplying the total number of texture units of the card by the core speed of the chip. The better the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Render Output Units 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 output rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.
GeForce GT 420
Radeon HD 5450