Compare any two graphics cards:
GeForce GTS 250 512MB vs Radeon HD 5770
IntroThe GeForce GTS 250 512MB has a core clock frequency of 738 MHz and a GDDR3 memory speed of 1100 MHz. It also features a 256-bit memory bus, and uses a 65/55 nm design. It is made up of 128 SPUs, 64 Texture Address Units, and 16 ROPs.
Compare those specifications to the Radeon HD 5770, which has a core clock speed of 850 MHz and a GDDR5 memory frequency of 1200 MHz. It also uses a 128-bit memory bus, and makes use of a 40 nm design. It is made up of 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
As far as performance goes, the Radeon HD 5770 should in theory be just a bit better than the GeForce GTS 250 512MB overall. (explain)
Texel RateThe GeForce GTS 250 512MB is much (more or less 39%) faster with regards to AF than the Radeon HD 5770. (explain)
Pixel RateThe Radeon HD 5770 should be just a bit (about 15%) better at FSAA than the GeForce GTS 250 512MB, and also able to handle higher 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: Memory bandwidth is the largest amount of data (counted in megabytes per second) that can be moved past the external memory interface within a second. The number is worked out by multiplying the card's bus width by the speed of its memory. If the card has DDR type memory, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, 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 amount of texture map elements (texels) that can be processed in one second. This figure is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The higher this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the most pixels the video card 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 sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.