Compare any two graphics cards:
GeForce GT 430 vs GeForce GT 640 DDR3
IntroThe GeForce GT 430 uses a 40 nm design. nVidia has clocked the core frequency at 700 MHz. The GDDR3 memory is set to run at a speed of 900 MHz on this card. It features 96 SPUs along with 16 TAUs and 4 ROPs.
Compare those specifications to the GeForce GT 640 DDR3, which has GPU clock speed of 900 MHz, and 2048 MB of DDR3 memory running at 1782 MHz through a 128-bit bus. It also features 384 Stream Processors, 32 TAUs, and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The GeForce GT 640 DDR3 should in theory be quite a bit faster than the GeForce GT 430 overall. (explain)
Texel RateThe GeForce GT 640 DDR3 is much (more or less 157%) faster with regards to anisotropic filtering than the GeForce GT 430. (explain)
Pixel RateIf running with a high resolution is important to you, then the GeForce GT 640 DDR3 is superior to the GeForce GT 430, by far. (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 maximum amount of data (counted in megabytes per second) that can be transported over the external memory interface in a second. The number is calculated by multiplying the bus width by the speed of its memory. If it uses DDR memory, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed per second. This is worked out by multiplying the total number of texture units of the card by the core clock speed of the chip. The better 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 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 number of colour ROPs by the the core 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 is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.