Compare any two graphics cards:
GeForce 8800 GT 1GB vs GeForce 9800 GT 512MB
IntroThe GeForce 8800 GT 1GB uses a 65 nm design. nVidia has set the core frequency at 600 MHz. The GDDR3 memory works at a frequency of 900 MHz on this particular model. It features 112 SPUs along with 56 Texture Address Units and 16 ROPs.
Compare those specs to the GeForce 9800 GT 512MB, which features core clock speeds of 600 MHz on the GPU, and 900 MHz on the 512 MB of GDDR3 memory. It features 112 SPUs along with 56 TAUs and 16 Rasterization Operator Units.
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
Both cards have the exact same bandwidth, so theoretically they should have identical performance. (explain)
Texel RateBoth cards have exactly the same texel fill rate, so theoretically they should perform equally good at at AF. (explain)
Pixel RateBoth cards have the exact same pixel rate, so theoretically they should perform equally good at at full screen anti-aliasing, and be capable of handling 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: Bandwidth is the maximum amount of information (counted in megabytes per second) that can be transferred across the external memory interface in one second. It is worked out by multiplying the interface width by its memory clock speed. In the case of DDR type RAM, the result should 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 AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This number is calculated by multiplying the total amount of texture units of the card by the core speed of the chip. The better the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.
Pixel Rate: Pixel rate is the most pixels the graphics card can possibly write to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the amount of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.