Compare any two graphics cards:
Radeon HD 4850 X2 1GB vs Radeon HD 5770
IntroThe Radeon HD 4850 X2 1GB makes use of a 55 nm design. AMD has clocked the core speed at 625 MHz. The GDDR3 memory works at a frequency of 993 MHz on this specific card. It features 800(160x5) SPUs along with 40 TAUs and 16 ROPs.
Compare all of that to the Radeon HD 5770, which features a GPU core clock speed of 850 MHz, and 1024 MB of GDDR5 RAM set to run at 1200 MHz through a 128-bit bus. It also is made up of 800(160x5) Stream Processors, 40 Texture Address Units, and 16 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 4850 X2 1GB should be 66% quicker than the Radeon HD 5770 in general, due to its greater bandwidth. (explain)
Texel RateThe Radeon HD 4850 X2 1GB is quite a bit (approximately 47%) faster with regards to texture filtering than the Radeon HD 5770. (explain)
Pixel RateThe Radeon HD 4850 X2 1GB should be much (about 47%) better at full screen anti-aliasing than the Radeon HD 5770, and also able to handle higher resolutions without losing too much performance. (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 max amount of information (in units of MB per second) that can be transported across the external memory interface within a second. It is worked out by multiplying the card's interface width by its memory clock speed. In the case of DDR RAM, it must be multiplied by 2 once again. If 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 higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied in one 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 this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly write to the local memory per second - measured in millions of pixels per second. The number is calculated 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 outputting the pixels (image) to the screen. The actual pixel output rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.