Compare any two graphics cards:
GeForce GTS 450 vs Radeon HD 3850 X2
IntroThe GeForce GTS 450 makes use of a 40 nm design. nVidia has clocked the core frequency at 783 MHz. The GDDR5 RAM runs at a frequency of 902 MHz on this card. It features 192 SPUs as well as 32 TAUs and 16 ROPs.
Compare those specs to the Radeon HD 3850 X2, which features GPU core speed of 668 MHz, and 512 MB of GDDR3 memory running at 828 MHz through a 256-bit bus. It also is made up of 320(64x5) SPUs, 16 Texture Address Units, and 16 ROPs.
Power Usage and Theoretical Benchmarks
The Radeon HD 3850 X2, in theory, should be a lot faster than the GeForce GTS 450 overall. (explain)
Texel RateThe GeForce GTS 450 is a small bit (approximately 17%) more effective at texture filtering than the Radeon HD 3850 X2. (explain)
Pixel RateIf using a high screen resolution is important to you, then the Radeon HD 3850 X2 is superior to the GeForce GTS 450, by a large margin. (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 (in units of megabytes per second) that can be moved over the external memory interface within a second. The number is calculated by multiplying the bus width by the speed of its memory. If the card has DDR type memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This is worked out by multiplying the total number of texture units of the card by the core clock speed of the chip. The better this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly write to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.