Compare any two graphics cards:
Radeon HD 3870 X2 1GB vs Radeon HD 5770
IntroThe Radeon HD 3870 X2 1GB makes use of a 55 nm design. AMD has set the core frequency at 825 MHz. The GDDR4 RAM is set to run at a speed of 1126 MHz on this specific model. It features 320(64x5) SPUs as well as 16 TAUs and 16 Rasterization Operator Units.
Compare those specs to the Radeon HD 5770, which comes with a core clock frequency of 850 MHz and a GDDR5 memory speed of 1200 MHz. It also uses a 128-bit memory bus, and uses a 40 nm design. It is comprised of 800(160x5) SPUs, 40 TAUs, and 16 Raster Operation Units.
Power Usage and Theoretical Benchmarks
The Radeon HD 3870 X2 1GB should in theory perform quite a bit faster than the Radeon HD 5770 in general. (explain)
Texel RateThe Radeon HD 5770 is much (more or less 29%) more effective at texture filtering than the Radeon HD 3870 X2 1GB. (explain)
Pixel RateIf running with a high resolution is important to you, then the Radeon HD 3870 X2 1GB is a better choice, by far. (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 data (in units of MB per second) that can be moved over the external memory interface in a second. The number is calculated by multiplying the bus width by its memory speed. In the case of DDR memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied per second. This is worked out by multiplying the total texture units of the card by the core speed of the chip. The better 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 maximum amount of pixels that the graphics chip can possibly record to its local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel 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 ability to reach the max fill rate.