Compare any two graphics cards:
Radeon HD 3850 X2 vs Radeon HD 6750
IntroThe Radeon HD 3850 X2 has core clock speeds of 668 MHz on the GPU, and 828 MHz on the 512 MB of GDDR3 memory. It features 320(64x5) SPUs along with 16 Texture Address Units and 16 ROPs.
Compare that to the Radeon HD 6750, which uses a 40 nm design. AMD has set the core frequency at 725 MHz. The GDDR5 RAM is set to run at a frequency of 1000 MHz on this model. It features 720 SPUs as well as 36 Texture Address Units and 16 ROPs.
Power Usage and Theoretical Benchmarks
In theory, the Radeon HD 3850 X2 is 66% faster than the Radeon HD 6750 overall, because of its greater bandwidth. (explain)
Texel RateThe Radeon HD 6750 is a lot (about 22%) better at anisotropic filtering than the Radeon HD 3850 X2. (explain)
Pixel RateIf running with high levels of AA is important to you, then the Radeon HD 3850 X2 is a better choice, and very much so. (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.
One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.
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 largest amount of data (in units of MB per second) that can be transferred across the external memory interface within a second. It is worked out by multiplying the interface width by its memory clock speed. If it uses DDR memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed in one second. This is worked out by multiplying the total number of texture units by the core speed of the chip. The better this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the most pixels the video card could possibly write to the local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.