Compare any two graphics cards:
Radeon HD 3850 256MB vs Radeon HD 4850 X2 1GB
IntroThe Radeon HD 3850 256MB makes use of a 55 nm design. AMD has set the core speed at 668 MHz. The GDDR3 memory works at a speed of 828 MHz on this card. It features 320(64x5) SPUs as well as 16 Texture Address Units and 16 ROPs.
Compare all of that to the Radeon HD 4850 X2 1GB, which comes with GPU clock speed of 625 MHz, and 1024 MB of GDDR3 RAM set to run at 993 MHz through a 256-bit bus. It also is comprised of 800(160x5) Stream Processors, 40 Texture Address Units, and 16 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the Radeon HD 4850 X2 1GB should in theory be a lot better than the Radeon HD 3850 256MB overall. (explain)
Texel RateThe Radeon HD 4850 X2 1GB should be much (about 368%) faster with regards to AF than the Radeon HD 3850 256MB. (explain)
Pixel RateThe Radeon HD 4850 X2 1GB should be quite a bit (more or less 87%) faster with regards to anti-aliasing than the Radeon HD 3850 256MB, and capable of handling higher screen 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 largest amount of information (in units of megabytes per second) that can be moved past the external memory interface in a second. It is calculated by multiplying the card's bus width by its memory clock speed. If the card has DDR type memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed in one second. This figure is worked out by multiplying the total number of texture units by the core speed of the chip. The higher the texel rate, the better the graphics 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 that the graphics card can possibly write to the local memory in one second - measured in millions of pixels per second. The number 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 also depends on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.