Compare any two graphics cards:
GeForce GTS 250 512MB vs Radeon HD 5770
IntroThe GeForce GTS 250 512MB features a core clock speed of 738 MHz and a GDDR3 memory frequency of 1100 MHz. It also uses 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 all of that to the Radeon HD 5770, which comes with a core clock speed of 850 MHz and a GDDR5 memory speed of 1200 MHz. It also makes use of a 128-bit memory bus, and uses a 40 nm design. It is comprised of 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 5770 is 9% quicker than the GeForce GTS 250 512MB in general, because of its greater bandwidth. (explain)
Texel RateThe GeForce GTS 250 512MB will be quite a bit (more or less 39%) better at texture filtering than the Radeon HD 5770. (explain)
Pixel RateIf running with a high resolution is important to you, then the Radeon HD 5770 is superior to the GeForce GTS 250 512MB, but only just. (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 transferred over the external memory interface in one second. It's worked out by multiplying the card's interface width by its memory clock speed. In the case of DDR type memory, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed per second. This number is calculated by multiplying the total amount of texture units by the core speed of the chip. The higher 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 maximum number of pixels the graphics card could possibly write to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the amount of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.