Compare any two graphics cards:
GeForce GTX 580 vs Radeon HD 4850 512MB
IntroThe GeForce GTX 580 has a clock speed of 772 MHz and a GDDR5 memory frequency of 1002 MHz. It also uses a 384-bit memory bus, and uses a 40 nm design. It features 512 SPUs, 64 TAUs, and 48 Raster Operation Units.
Compare that to the Radeon HD 4850 512MB, which has a GPU core clock speed of 625 MHz, and 512 MB of GDDR3 memory set to run at 993 MHz through a 256-bit bus. It also is made up of 800(160x5) SPUs, 40 TAUs, and 16 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The GeForce GTX 580 should theoretically perform a lot faster than the Radeon HD 4850 512MB overall. (explain)
Texel RateThe GeForce GTX 580 is much (about 98%) faster with regards to anisotropic filtering than the Radeon HD 4850 512MB. (explain)
Pixel RateThe GeForce GTX 580 will be quite a bit (about 271%) faster with regards to full screen anti-aliasing than the Radeon HD 4850 512MB, and also should be capable of handling higher screen resolutions without losing too much performance. (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 maximum amount of data (measured in megabytes per second) that can be transferred past the external memory interface in a second. The number is calculated by multiplying the card's interface width by the speed of its memory. If it uses DDR type RAM, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the better 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 texture map elements (texels) that can be processed per second. This figure is calculated by multiplying the total amount of texture units by the core speed of the chip. The higher this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.
Pixel Rate: Pixel rate is the most pixels that the graphics card could possibly write to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the amount of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.