Compare any two graphics cards:
GeForce 8800 GT 512MB vs GeForce 9800 GT 1GB
IntroThe GeForce 8800 GT 512MB uses a 65 nm design. nVidia has clocked the core frequency at 600 MHz. The GDDR3 RAM is set to run at a frequency of 900 MHz on this card. It features 112 SPUs along with 56 TAUs and 16 Rasterization Operator Units.
Compare those specifications to the GeForce 9800 GT 1GB, which uses a 65/55 nm design. nVidia has clocked the core speed at 600 MHz. The GDDR3 RAM is set to run at a frequency of 900 MHz on this particular model. It features 112 SPUs as well as 56 Texture Address Units and 16 Rasterization Operator Units.
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
Both cards have the exact same bandwidth, so in theory they should have identical performance. (explain)
Texel RateBoth cards have the exact same texel rate, so in theory they should be equally good at at AF. (explain)
Pixel RateBoth cards have exactly the same pixel fill rate, so theoretically they should perform equally good at at AA, and be able to handle the same screen 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 largest amount of data (counted in MB per second) that can be transferred over the external memory interface in one second. It's calculated by multiplying the interface width by the speed of its memory. In the case of DDR type RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied in one second. This number is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the most pixels that the graphics card could possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.