Compare any two graphics cards:
GeForce GTX 280 vs Radeon HD 4850 X2 1GB
IntroThe GeForce GTX 280 makes use of a 65 nm design. nVidia has set the core speed at 602 MHz. The GDDR3 RAM is set to run at a speed of 1107 MHz on this model. It features 240 SPUs as well as 80 Texture Address Units and 32 ROPs.
Compare those specifications to the Radeon HD 4850 X2 1GB, which features a clock speed of 625 MHz and a GDDR3 memory speed of 993 MHz. It also features a 256-bit bus, and uses a 55 nm design. It is made up of 800(160x5) SPUs, 40 Texture Address Units, and 16 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The GeForce GTX 280 should theoretically perform a little bit faster than the Radeon HD 4850 X2 1GB in general. (explain)
Texel RateThe Radeon HD 4850 X2 1GB will be a bit (more or less 4%) more effective at texture filtering than the GeForce GTX 280. (explain)
Pixel RateIf running with lots of anti-aliasing is important to you, then the Radeon HD 4850 X2 1GB is superior to the GeForce GTX 280, but only just. (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 (in units of MB per second) that can be transported across the external memory interface in one second. It's worked out by multiplying the card's interface width by its memory clock speed. If the card has DDR memory, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed in one second. This is calculated by multiplying the total texture units of the card by the core speed of the chip. The higher this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.
Pixel Rate: Pixel rate is the most pixels the graphics card could possibly write to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.