Compare any two graphics cards:
Radeon HD 4850 X2 1GB vs Radeon HD 5750 1GB
IntroThe Radeon HD 4850 X2 1GB has a GPU clock speed of 625 MHz, and the 1024 MB of GDDR3 RAM runs at 993 MHz through a 256-bit bus. It also is comprised of 800(160x5) SPUs, 40 TAUs, and 16 ROPs.
Compare those specs to the Radeon HD 5750 1GB, which features core clock speeds of 700 MHz on the GPU, and 1150 MHz on the 1024 MB of GDDR5 RAM. It features 720(144x5) SPUs along with 36 Texture Address Units and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 4850 X2 1GB should perform a lot faster than the Radeon HD 5750 1GB in general. (explain)
Texel RateThe Radeon HD 4850 X2 1GB will be much (about 98%) more effective at anisotropic filtering than the Radeon HD 5750 1GB. (explain)
Pixel RateIf running with high levels of AA is important to you, then the Radeon HD 4850 X2 1GB is superior to the Radeon HD 5750 1GB, 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: Memory bandwidth is the largest amount of data (measured in MB per second) that can be moved past the external memory interface in a second. It's calculated by multiplying the interface width by its memory speed. In the case of DDR type RAM, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed per second. This figure is calculated by multiplying the total amount of texture units of the card by the core speed of the chip. The better the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly record to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the number of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.