Compare any two graphics cards:
GeForce 8400 GS 512MB vs GeForce 8600 GS (OEM)
IntroThe GeForce 8400 GS 512MB has a clock frequency of 650 MHz and a DDR2 memory frequency of 400 MHz. It also uses a 64-bit memory bus, and makes use of a 80 nm design. It features 16 SPUs, 8 Texture Address Units, and 4 Raster Operation Units.
Compare those specs to the GeForce 8600 GS (OEM), which has a clock frequency of 540 MHz and a DDR2 memory frequency of 400 MHz. It also uses a 128-bit memory bus, and uses a 80 nm design. It is comprised of 32 SPUs, 16 TAUs, and 8 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically, the GeForce 8600 GS (OEM) should perform much faster than the GeForce 8400 GS 512MB overall. (explain)
Texel RateThe GeForce 8600 GS (OEM) should be much (about 66%) more effective at AF than the GeForce 8400 GS 512MB. (explain)
Pixel RateIf running with high levels of AA is important to you, then the GeForce 8600 GS (OEM) is superior to the GeForce 8400 GS 512MB, by a large margin. (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 data (counted in MB per second) that can be moved across the external memory interface in a second. It is calculated by multiplying the card's bus width by its memory speed. In the case of DDR type memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied in one second. This is calculated by multiplying the total texture units of the card by the core clock 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 a second.
Pixel Rate: Pixel rate is the most pixels the video card can possibly record to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.