Compare any two graphics cards:
GeForce GTS 450 vs Radeon HD 6750
IntroThe GeForce GTS 450 has core clock speeds of 783 MHz on the GPU, and 902 MHz on the 512 MB of GDDR5 RAM. It features 192 SPUs as well as 32 Texture Address Units and 16 Rasterization Operator Units.
Compare all that to the Radeon HD 6750, which uses a 40 nm design. AMD has clocked the core frequency at 725 MHz. The GDDR5 RAM works at a speed of 1000 MHz on this specific model. It features 720 SPUs along with 36 Texture Address Units and 16 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically, the Radeon HD 6750 should perform a little bit faster than the GeForce GTS 450 in general. (explain)
Texel RateThe Radeon HD 6750 is a small bit (about 4%) more effective at anisotropic filtering than the GeForce GTS 450. (explain)
Pixel RateThe GeForce GTS 450 should be a little bit (about 8%) better at anti-aliasing than the Radeon HD 6750, and should be capable of handling higher 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.
Memory Bandwidth: Memory bandwidth is the max amount of data (measured in megabytes per second) that can be moved across the external memory interface in one second. The number is worked out by multiplying the bus width by its memory speed. In the case of DDR type memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed per second. This is worked out by multiplying the total number of texture units by the core clock speed of the chip. The higher the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.
Pixel Rate: Pixel rate is the most pixels the video card can possibly record to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.