Compare any two graphics cards:
GeForce 9800 GT 1GB vs GeForce 9800 GT 512MB
IntroThe GeForce 9800 GT 1GB uses a 65/55 nm design. nVidia has clocked the core speed at 600 MHz. The GDDR3 RAM runs at a frequency of 900 MHz on this model. It features 112 SPUs as well as 56 Texture Address Units and 16 ROPs.
Compare those specs to the GeForce 9800 GT 512MB, which comes with GPU clock speed of 600 MHz, and 512 MB of GDDR3 memory running at 900 MHz through a 256-bit bus. It also features 112 Stream Processors, 56 Texture Address Units, and 16 ROPs.
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
Both cards have exactly the same memory bandwidth, so in theory they should perform the same. (explain)
Texel RateBoth cards have exactly the same texel rate, so theoretically they should be equally good at at anisotropic filtering. (explain)
Pixel RateBoth cards have the exact same pixel fill rate, so theoretically they should be equally good at at FSAA, and be able to handle the same resolutions. (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: Memory bandwidth is the maximum amount of information (in units of MB per second) that can be moved over the external memory interface within a second. It's worked out by multiplying the bus width by its memory clock speed. In the case of DDR type RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. 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 texture map elements (texels) that can be applied per second. This is calculated by multiplying the total amount of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly record to its local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the max fill rate.