Compare any two graphics cards:
GeForce 8600 GT 256MB DDR2 vs Radeon HD 5550
IntroThe GeForce 8600 GT 256MB DDR2 makes use of a 80 nm design. nVidia has clocked the core speed at 540 MHz. The DDR2 RAM runs at a speed of 400 MHz on this model. It features 32 SPUs as well as 16 TAUs and 8 ROPs.
Compare all of that to the Radeon HD 5550, which comes with clock speeds of 550 MHz on the GPU, and 400 MHz on the 512 MB of DDR2 RAM. It features 320(64x5) SPUs as well as 16 TAUs and 8 ROPs.
Power Usage and Theoretical Benchmarks
Both cards have exactly the same bandwidth, so theoretically they should have identical performance. (explain)
Texel RateThe Radeon HD 5550 is a small bit (about 2%) better at anisotropic filtering than the GeForce 8600 GT 256MB DDR2. (explain)
Pixel RateIf using high levels of AA is important to you, then the Radeon HD 5550 is a better choice, but it probably won't make a huge difference. (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: Memory bandwidth is the max amount of information (counted in megabytes per second) that can be transferred across the external memory interface in one second. It is worked out by multiplying the card's interface width by its memory clock speed. If it uses DDR RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better 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 can be processed per second. This number is worked out by multiplying the total number of texture units of the card by the core clock 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 the graphics card could possibly write to its local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the max fill rate.