Compare any two graphics cards:
GeForce 8600 GT 512MB DDR2 vs GeForce GTX 590
IntroThe GeForce 8600 GT 512MB DDR2 comes with a GPU clock speed of 540 MHz, and the 512 MB of DDR2 RAM is set to run at 400 MHz through a 128-bit bus. It also features 32 SPUs, 16 Texture Address Units, and 8 Raster Operation Units.
Compare those specifications to the GeForce GTX 590, which has a clock speed of 607 MHz and a GDDR5 memory speed of 855 MHz. It also uses a 384-bit bus, and makes use of a 40 nm design. It is made up of 512 SPUs, 64 TAUs, and 48 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically, the GeForce GTX 590 should perform quite a bit faster than the GeForce 8600 GT 512MB DDR2 in general. (explain)
Texel RateThe GeForce GTX 590 should be much (more or less 799%) faster with regards to anisotropic filtering than the GeForce 8600 GT 512MB DDR2. (explain)
Pixel RateThe GeForce GTX 590 is a lot (more or less 1249%) better at anti-aliasing than the GeForce 8600 GT 512MB DDR2, and also will be capable of handling higher screen 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.
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.
Memory Bandwidth: Memory bandwidth is the largest amount of data (in units of megabytes per second) that can be moved across the external memory interface within a second. It's calculated by multiplying the card's interface width by the speed of its memory. In the case of DDR RAM, the result should 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 AA, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied in one second. This is worked out by multiplying the total amount of texture units by the core speed of the chip. The higher this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly write to the local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.