Compare any two graphics cards:
GeForce GTS 450 1GB vs Radeon HD 6770
IntroThe GeForce GTS 450 1GB comes with a GPU core speed of 783 MHz, and the 1024 MB of GDDR5 memory is set to run at 902 MHz through a 128-bit bus. It also is made up of 192 SPUs, 32 Texture Address Units, and 16 Raster Operation Units.
Compare those specs to the Radeon HD 6770, which comes with GPU clock speed of 900 MHz, and 512 MB of GDDR5 RAM running at 1050 MHz through a 128-bit bus. It also features 800 Stream Processors, 40 TAUs, and 16 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 6770 should perform a bit faster than the GeForce GTS 450 1GB in general. (explain)
Texel RateThe Radeon HD 6770 will be quite a bit (about 44%) faster with regards to texture filtering than the GeForce GTS 450 1GB. (explain)
Pixel RateIf using lots of anti-aliasing is important to you, then the Radeon HD 6770 is superior to the GeForce GTS 450 1GB, but only just. (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 (measured in MB per second) that can be moved across the external memory interface within a second. It's calculated by multiplying the card's interface width by its memory clock speed. In the case of DDR type memory, the result should be multiplied by 2 again. If 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 higher screen resolutions.
Texel Rate: Texel rate is the maximum number 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 higher this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly record to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.