Compare any two graphics cards:
GeForce GTS 450 1GB vs Radeon HD 3870 512MB
IntroThe GeForce GTS 450 1GB has a clock speed of 783 MHz and a GDDR5 memory frequency of 902 MHz. It also uses a 128-bit bus, and makes use of a 40 nm design. It is comprised of 192 SPUs, 32 Texture Address Units, and 16 Raster Operation Units.
Compare all of that to the Radeon HD 3870 512MB, which comes with a GPU core clock speed of 775 MHz, and 512 MB of GDDR3 memory set to run at 900 MHz through a 256-bit bus. It also is made up of 320(64x5) SPUs, 16 Texture Address Units, and 16 ROPs.
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
Theoretically, the GeForce GTS 450 1GB should perform a small bit faster than the Radeon HD 3870 512MB in general. (explain)
Texel RateThe GeForce GTS 450 1GB is much (about 102%) faster with regards to AF than the Radeon HD 3870 512MB. (explain)
Pixel RateThe GeForce GTS 450 1GB should be a bit (approximately 1%) faster with regards to AA than the Radeon HD 3870 512MB, and also should be able to handle 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.
Please note that the price comparisons are based on search keywords - sometimes it might show cards with very similar names that are not exactly the same as the one chosen in the comparison. We do try to filter out the wrong results as best we can, though.
Memory Bandwidth: Bandwidth is the max amount of data (measured in MB per second) that can be moved across the external memory interface within a second. The number is worked out by multiplying the card's bus width by its memory speed. If it uses DDR memory, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better 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 amount of texture map elements (texels) that are applied in one second. This number is calculated by multiplying the total texture units by the core clock speed of the chip. The better this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly write to the 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 card's clock speed. 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 is also dependant 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.