Compare any two graphics cards:
GeForce GT 240 GDDR5 vs Radeon HD 4850 X2 1GB
IntroThe GeForce GT 240 GDDR5 has clock speeds of 550 MHz on the GPU, and 850 MHz on the 512 MB of GDDR5 RAM. It features 96 SPUs as well as 32 Texture Address Units and 8 Rasterization Operator Units.
Compare those specs to the Radeon HD 4850 X2 1GB, which comes with a GPU core clock speed of 625 MHz, and 1024 MB of GDDR3 memory set to run at 993 MHz through a 256-bit bus. It also features 800(160x5) Stream Processors, 40 TAUs, and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 4850 X2 1GB should be 134% faster than the GeForce GT 240 GDDR5 in general, due to its greater bandwidth. (explain)
Texel RateThe Radeon HD 4850 X2 1GB is a lot (about 184%) faster with regards to anisotropic filtering than the GeForce GT 240 GDDR5. (explain)
Pixel RateThe Radeon HD 4850 X2 1GB is a lot (more or less 355%) more effective at AA than the GeForce GT 240 GDDR5, and should be able to handle higher resolutions more effectively. (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: Memory bandwidth is the largest amount of information (measured in megabytes per second) that can be transported across the external memory interface in a second. It is worked out by multiplying the card's bus width by its memory speed. If it uses DDR type memory, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the better 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 can be processed in one second. This number is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The better this number, the better the 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 most pixels that the graphics chip could possibly record to its local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the max fill rate.