Compare any two graphics cards:
Geforce GTX 680 vs Radeon HD 4850 1GB
IntroThe Geforce GTX 680 makes use of a 28 nm design. nVidia has clocked the core speed at 1006 MHz. The GDDR5 RAM is set to run at a speed of 1502 MHz on this model. It features 1536 SPUs as well as 128 Texture Address Units and 32 Rasterization Operator Units.
Compare that to the Radeon HD 4850 1GB, which features a core clock frequency of 625 MHz and a GDDR4 memory frequency of 993 MHz. It also uses 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)
In theory, the Geforce GTX 680 should be 203% quicker than the Radeon HD 4850 1GB in general, because of its higher data rate. (explain)
Texel RateThe Geforce GTX 680 will be quite a bit (more or less 415%) faster with regards to anisotropic filtering than the Radeon HD 4850 1GB. (explain)
Pixel RateThe Geforce GTX 680 should be a lot (more or less 222%) better at AA than the Radeon HD 4850 1GB, and should be capable of handling higher screen resolutions more effectively. (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.
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 largest amount of data (measured in megabytes per second) that can be moved past the external memory interface in a second. The number is worked out by multiplying the card's bus width by its memory speed. If the card has DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, 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 worked out by multiplying the total texture units by the core speed of the chip. The better this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly write to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the number of colour ROPs by the the core 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 output rate also depends on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.