Compare any two graphics cards:
GeForce 9800 GX2 vs Radeon HD 4870 512MB
IntroThe GeForce 9800 GX2 has a GPU clock speed of 600 MHz, and the 512 MB of GDDR3 memory runs at 1000 MHz through a 256-bit bus. It also is comprised of 128 SPUs, 64 TAUs, and 16 Raster Operation Units.
Compare those specifications to the Radeon HD 4870 512MB, which comes with core clock speeds of 750 MHz on the GPU, and 900 MHz on the 512 MB of GDDR5 RAM. It features 800(160x5) SPUs along with 40 TAUs and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the GeForce 9800 GX2 should perform a small bit faster than the Radeon HD 4870 512MB overall. (explain)
Texel RateThe GeForce 9800 GX2 is quite a bit (approximately 156%) faster with regards to anisotropic filtering than the Radeon HD 4870 512MB. (explain)
Pixel RateIf running with a high resolution is important to you, then the GeForce 9800 GX2 is superior to the Radeon HD 4870 512MB, and very much so. (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.
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 (in units of megabytes per second) that can be moved over the external memory interface in a second. It is worked out by multiplying the interface width by its memory speed. In the case of DDR type memory, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the better the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed in one second. This number is calculated by multiplying the total amount of texture units by the core clock speed of the chip. The better the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the most pixels the video card could possibly record to the local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill 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 maximum fill rate.