Compare any two graphics cards:
Geforce GTX 680 vs Radeon HD 4850 1GB
IntroThe Geforce GTX 680 comes with a GPU clock speed of 1006 MHz, and the 2048 MB of GDDR5 memory is set to run at 1502 MHz through a 256-bit bus. It also is comprised of 1536 Stream Processors, 128 TAUs, and 32 ROPs.
Compare all of that to the Radeon HD 4850 1GB, which features core clock speeds of 625 MHz on the GPU, and 993 MHz on the 1024 MB of GDDR4 RAM. It features 800(160x5) SPUs along with 40 TAUs and 16 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Geforce GTX 680 is 203% quicker than the Radeon HD 4850 1GB overall, due to its higher bandwidth. (explain)
Texel RateThe Geforce GTX 680 will be a lot (more or less 415%) better at anisotropic filtering than the Radeon HD 4850 1GB. (explain)
Pixel RateThe Geforce GTX 680 will be quite a bit (about 222%) better at FSAA than the Radeon HD 4850 1GB, and also 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 (in units of megabytes per second) that can be transported across the external memory interface within a second. It's worked out by multiplying the bus width by its memory speed. If the card has DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed in one second. This figure is worked out by multiplying the total number of texture units of the card by the core speed of the chip. The better the texel rate, the better the graphics 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 most pixels that the graphics chip can possibly write to the local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.