Compare any two graphics cards:
Geforce GTX 680 vs Radeon HD 4850 1GB
IntroThe Geforce GTX 680 comes with a clock frequency of 1006 MHz and a GDDR5 memory speed of 1502 MHz. It also features a 256-bit memory bus, and makes use of a 28 nm design. It features 1536 SPUs, 128 Texture Address Units, and 32 ROPs.
Compare all that to the Radeon HD 4850 1GB, which has a core clock speed of 625 MHz and a GDDR4 memory speed of 993 MHz. It also uses a 256-bit bus, and makes use of a 55 nm design. It is comprised of 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Geforce GTX 680 should theoretically perform quite a bit faster than the Radeon HD 4850 1GB overall. (explain)
Texel RateThe Geforce GTX 680 is much (more or less 415%) faster with regards to AF than the Radeon HD 4850 1GB. (explain)
Pixel RateThe Geforce GTX 680 is a lot (approximately 222%) better at AA than the Radeon HD 4850 1GB, and will be able to handle higher screen 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.
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 (in units of MB per second) that can be transported across the external memory interface in one second. It's worked out by multiplying the card's interface width by its memory speed. If it uses DDR RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, 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 applied per second. This is calculated by multiplying the total amount of texture units of the card by the core speed of the chip. The better the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the most pixels the graphics card can possibly write to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.