Compare any two graphics cards:
GeForce GTX 580 vs Radeon HD 6770
IntroThe GeForce GTX 580 comes with a clock frequency of 772 MHz and a GDDR5 memory frequency of 1002 MHz. It also features a 384-bit bus, and uses a 40 nm design. It is made up of 512 SPUs, 64 Texture Address Units, and 48 Raster Operation Units.
Compare that to the Radeon HD 6770, which comes with a GPU core clock speed of 900 MHz, and 512 MB of GDDR5 RAM set to run at 1050 MHz through a 128-bit bus. It also is comprised of 800 SPUs, 40 TAUs, and 16 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the GeForce GTX 580 will be 186% quicker than the Radeon HD 6770 in general, because of its greater bandwidth. (explain)
Texel RateThe GeForce GTX 580 will be much (more or less 37%) faster with regards to anisotropic filtering than the Radeon HD 6770. (explain)
Pixel RateThe GeForce GTX 580 should be quite a bit (approximately 157%) more effective at FSAA than the Radeon HD 6770, and will be able to handle higher resolutions while still performing well. (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.
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 transported over the external memory interface in a second. It's calculated by multiplying the card's bus width by its memory clock speed. In the case of DDR memory, it should be multiplied by 2 once again. If it uses 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 high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed in one second. This is worked out by multiplying the total texture units by the core clock speed of the chip. The better this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.