Compare any two graphics cards:
GeForce GT 240 GDDR5 vs Radeon HD 4850 X2 1GB
IntroThe GeForce GT 240 GDDR5 comes with a clock frequency of 550 MHz and a GDDR5 memory speed of 850 MHz. It also features a 128-bit bus, and uses a 40 nm design. It is comprised of 96 SPUs, 32 TAUs, and 8 Raster Operation Units.
Compare those specifications to the Radeon HD 4850 X2 1GB, which features a clock frequency of 625 MHz and a GDDR3 memory frequency of 993 MHz. It also features a 256-bit bus, and uses a 55 nm design. It is comprised of 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 4850 X2 1GB will be 134% faster than the GeForce GT 240 GDDR5 overall, due to its higher bandwidth. (explain)
Texel RateThe Radeon HD 4850 X2 1GB should be quite a bit (more or less 184%) more effective at anisotropic filtering than the GeForce GT 240 GDDR5. (explain)
Pixel RateThe Radeon HD 4850 X2 1GB will be quite a bit (approximately 355%) faster with regards to full screen anti-aliasing than the GeForce GT 240 GDDR5, and also able to handle higher 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.
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 data (measured in MB per second) that can be transported past the external memory interface in one second. The number is calculated by multiplying the card's interface width by its memory clock speed. In the case of DDR type RAM, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the bandwidth is, 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 amount of texture map elements (texels) that can be processed in one second. This number is worked out by multiplying the total texture units of the card by the core 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 in one second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly write to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the amount of ROPs by the clock speed of the card. 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 rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.