Compare any two graphics cards:
GeForce 9800 GX2 vs Radeon HD 4870 512MB
IntroThe GeForce 9800 GX2 features a clock speed of 600 MHz and a GDDR3 memory frequency of 1000 MHz. It also uses a 256-bit memory bus, and uses a 65 nm design. It is made up of 128 SPUs, 64 Texture Address Units, and 16 ROPs.
Compare all that to the Radeon HD 4870 512MB, which has core clock speeds of 750 MHz on the GPU, and 900 MHz on the 512 MB of GDDR5 memory. It features 800(160x5) SPUs along with 40 Texture Address Units and 16 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The GeForce 9800 GX2 should theoretically perform a small bit faster than the Radeon HD 4870 512MB overall. (explain)
Texel RateThe GeForce 9800 GX2 will be quite a bit (about 156%) faster with regards to texture 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 max amount of information (counted in megabytes per second) that can be transported over the external memory interface in one second. The number is worked out by multiplying the bus width by its memory clock speed. If it uses DDR RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied per second. This number is calculated by multiplying the total amount of texture units by the core clock speed of the chip. The higher the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly write to its local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to 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 memory bandwidth is, the lower the potential to reach the maximum fill rate.