Compare any two graphics cards:
GeForce GT 640 DDR3 vs GeForce GTX 550 Ti
IntroThe GeForce GT 640 DDR3 has core speeds of 900 MHz on the GPU, and 1782 MHz on the 2048 MB of DDR3 RAM. It features 384 SPUs along with 32 Texture Address Units and 16 ROPs.
Compare those specifications to the GeForce GTX 550 Ti, which comes with core clock speeds of 900 MHz on the GPU, and 1026 MHz on the 1024 MB of GDDR5 memory. It features 192 SPUs along with 32 Texture Address Units and 24 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The GeForce GTX 550 Ti should theoretically be much faster than the GeForce GT 640 DDR3 in general. (explain)
Texel RateBoth cards have the exact same texel rate, so theoretically they should be equally good at at anisotropic filtering. (explain)
Pixel RateIf running with a high resolution is important to you, then the GeForce GTX 550 Ti is superior to the GeForce GT 640 DDR3, and very much so. (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 max amount of data (in units of megabytes per second) that can be transferred over the external memory interface in one second. It is worked out by multiplying the interface width by the speed of its memory. If it uses DDR RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed per second. This figure is calculated by multiplying the total texture units by the core clock 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 in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly write to its local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the max fill rate.