Compare any two graphics cards:
GeForce GT 240 GDDR5 vs Radeon HD 4850 X2 1GB
IntroThe GeForce GT 240 GDDR5 has a clock speed 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 features 96 SPUs, 32 Texture Address Units, and 8 Raster Operation Units.
Compare those specifications to the Radeon HD 4850 X2 1GB, which features GPU clock speed of 625 MHz, and 1024 MB of GDDR3 RAM running at 993 MHz through a 256-bit bus. It also is made up of 800(160x5) Stream Processors, 40 Texture Address Units, and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 4850 X2 1GB, in theory, should perform a lot faster than the GeForce GT 240 GDDR5 overall. (explain)
Texel RateThe Radeon HD 4850 X2 1GB should be much (about 184%) better at AF than the GeForce GT 240 GDDR5. (explain)
Pixel RateThe Radeon HD 4850 X2 1GB is quite a bit (about 355%) faster with regards to full screen anti-aliasing than the GeForce GT 240 GDDR5, and also will be 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: Bandwidth is the max amount of information (in units of MB per second) that can be transported across the external memory interface in one second. It is worked out by multiplying the card's interface width by the speed of its memory. If it uses DDR type RAM, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster 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 per second. This number is worked out by multiplying the total texture units of the card by the core speed of the chip. The better 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 maximum amount of pixels that the graphics card can possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.