Compare any two graphics cards:
GeForce GTX 260 216SP 55 nm vs Radeon R9 M380
IntroThe GeForce GTX 260 216SP 55 nm has a GPU core speed of 576 MHz, and the 896 MB of GDDR3 memory is set to run at 999 MHz through a 448-bit bus. It also features 216 Stream Processors, 72 Texture Address Units, and 28 Raster Operation Units.
Compare those specs to the Radeon R9 M380, which has a GPU core clock speed of 1000 MHz, and 4096 MB of GDDR5 memory set to run at 1500 MHz through a 128-bit bus. It also is made up of 640 SPUs, 40 TAUs, and 16 ROPs.
Power Usage and Theoretical Benchmarks
The GeForce GTX 260 216SP 55 nm should theoretically perform a bit faster than the Radeon R9 M380 in general. (explain)
Texel RateThe GeForce GTX 260 216SP 55 nm will be a little bit (about 4%) faster with regards to AF than the Radeon R9 M380. (explain)
Pixel RateThe GeForce GTX 260 216SP 55 nm is a little bit (more or less 1%) faster with regards to full screen anti-aliasing than the Radeon R9 M380, and should be capable of handling 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.
Memory Bandwidth: Bandwidth is the largest amount of information (measured in megabytes per second) that can be transported past the external memory interface in one second. The number is worked out by multiplying the interface width by the speed of its memory. If it uses DDR type RAM, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better 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 can be applied per second. This is calculated by multiplying the total number of texture units of the card by the core speed of the chip. The higher this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly record to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.