Compare any two graphics cards:
GeForce GT 430 vs GeForce GT 640 DDR3
IntroThe GeForce GT 430 has clock speeds of 700 MHz on the GPU, and 900 MHz on the 512 MB of GDDR3 memory. It features 96 SPUs along with 16 TAUs and 4 ROPs.
Compare that to the GeForce GT 640 DDR3, which makes use of a 28 nm design. nVidia has set the core frequency at 900 MHz. The DDR3 RAM runs at a frequency of 1782 MHz on this specific model. It features 384 SPUs along with 32 Texture Address Units and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the GeForce GT 640 DDR3 should in theory be much superior to the GeForce GT 430 in general. (explain)
Texel RateThe GeForce GT 640 DDR3 is a lot (approximately 157%) better at AF than the GeForce GT 430. (explain)
Pixel RateThe GeForce GT 640 DDR3 is much (more or less 414%) more effective at AA than the GeForce GT 430, and also should be able to handle higher resolutions without losing too much performance. (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 megabytes per second) that can be transferred past the external memory interface in one second. It is calculated by multiplying the card's bus width by its memory clock speed. If it uses DDR type memory, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed in one second. This number is calculated by multiplying the total texture units of the card by the core clock speed of the chip. The better the texel rate, the better the graphics 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 that the graphics chip could possibly write to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the amount of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.