Compare any two graphics cards:
GeForce 9800 GX2 vs GeForce GTX 280
IntroThe GeForce 9800 GX2 uses a 65 nm design. nVidia has set the core frequency at 600 MHz. The GDDR3 memory works at a frequency of 1000 MHz on this model. It features 128 SPUs along with 64 Texture Address Units and 16 Rasterization Operator Units.
Compare those specs to the GeForce GTX 280, which uses a 65 nm design. nVidia has clocked the core speed at 602 MHz. The GDDR3 RAM runs at a frequency of 1107 MHz on this model. It features 240 SPUs as well as 80 TAUs and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the GeForce GTX 280 is 11% faster than the GeForce 9800 GX2 overall, due to its higher data rate. (explain)
Texel RateThe GeForce 9800 GX2 will be quite a bit (approximately 59%) more effective at texture filtering than the GeForce GTX 280. (explain)
Pixel RateThe GeForce GTX 280 should be a bit (about 0%) more effective at anti-aliasing than the GeForce 9800 GX2, and should be able to handle higher screen resolutions while still performing well. (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.
One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.
Memory Bandwidth: Memory bandwidth is the largest amount of information (measured in MB per second) that can be transferred past the external memory interface in a second. It's calculated by multiplying the card's interface width by its memory speed. In the case of DDR RAM, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the bandwidth is, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed per second. This number is worked out 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 video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.
Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly write to the local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the amount of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.