Compare any two graphics cards:
GeForce GT 240 GDDR5 vs Radeon HD 4850 X2 1GB
IntroThe GeForce GT 240 GDDR5 comes with a core clock frequency of 550 MHz and a GDDR5 memory speed of 850 MHz. It also makes use of a 128-bit memory bus, and makes use of a 40 nm design. It is comprised of 96 SPUs, 32 TAUs, and 8 Raster Operation Units.
Compare all that to the Radeon HD 4850 X2 1GB, which uses a 55 nm design. AMD has set the core speed at 625 MHz. The GDDR3 RAM runs at a frequency of 993 MHz on this particular model. It features 800(160x5) SPUs along with 40 Texture Address Units and 16 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically, the Radeon HD 4850 X2 1GB should perform a lot faster than the GeForce GT 240 GDDR5 overall. (explain)
Texel RateThe Radeon HD 4850 X2 1GB will be much (more or less 184%) better at anisotropic filtering than the GeForce GT 240 GDDR5. (explain)
Pixel RateIf running with a high screen resolution is important to you, then the Radeon HD 4850 X2 1GB is the winner, by far. (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 (measured in megabytes per second) that can be moved over the external memory interface in one second. The number is worked out by multiplying the card's interface width by its memory clock speed. If the card has DDR type memory, it should be multiplied by 2 once 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, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed in one second. This figure is calculated by multiplying the total amount of texture units of the card by the core speed of the chip. The higher this number, the better the video 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 the video card can possibly write to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the number of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.