Compare any two graphics cards:
GeForce 8600 GT 256MB DDR2 vs Radeon HD 5550
IntroThe GeForce 8600 GT 256MB DDR2 features a GPU core clock speed of 540 MHz, and the 256 MB of DDR2 memory is set to run at 400 MHz through a 128-bit bus. It also is comprised of 32 Stream Processors, 16 Texture Address Units, and 8 Raster Operation Units.
Compare those specifications to the Radeon HD 5550, which comes with core clock speeds of 550 MHz on the GPU, and 400 MHz on the 512 MB of DDR2 RAM. It features 320(64x5) SPUs along with 16 Texture Address Units and 8 ROPs.
Power Usage and Theoretical Benchmarks
Both cards have the exact same bandwidth, so theoretically they should have identical performance. (explain)
Texel RateThe Radeon HD 5550 should be a small bit (more or less 2%) better at anisotropic filtering than the GeForce 8600 GT 256MB DDR2. (explain)
Pixel RateThe Radeon HD 5550 should be a small bit (more or less 2%) better at anti-aliasing than the GeForce 8600 GT 256MB DDR2, and also should be able to handle higher resolutions more effectively. (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 information (in units of MB per second) that can be transferred over the external memory interface within a second. It's calculated by multiplying the interface width by its memory clock speed. In the case of DDR memory, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed per second. This figure is calculated 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 graphics card will be at 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 chip could possibly write to the local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the amount of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.