Compare any two graphics cards:
GeForce 8800 GT 512MB vs GeForce 9800 GT 1GB
IntroThe GeForce 8800 GT 512MB features a core clock speed of 600 MHz and a GDDR3 memory speed of 900 MHz. It also uses a 256-bit bus, and makes use of a 65 nm design. It is made up of 112 SPUs, 56 TAUs, and 16 Raster Operation Units.
Compare those specifications to the GeForce 9800 GT 1GB, which comes with core speeds of 600 MHz on the GPU, and 900 MHz on the 1024 MB of GDDR3 memory. It features 112 SPUs along with 56 TAUs and 16 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
Both cards have the exact same memory bandwidth, so in theory they should have the same performance. (explain)
Texel RateBoth cards have exactly the same texel fill rate, so in theory they should be equally good at at AF. (explain)
Pixel RateBoth cards have exactly the same pixel fill rate, so in theory they should be equally good at at FSAA, 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 maximum amount of data (measured in MB per second) that can be transported over the external memory interface in one second. It is worked out by multiplying the card's interface width by the speed of its memory. If it uses DDR RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster 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 texture map elements (texels) that can be processed per second. This is calculated by multiplying the total texture units by the core clock 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 a second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly write to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the max fill rate.