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 as well as 16 Texture Address Units and 4 ROPs.
Compare those specs to the GeForce GT 640 DDR3, which features GPU core speed of 900 MHz, and 2048 MB of DDR3 RAM running at 1782 MHz through a 128-bit bus. It also is made up of 384 Stream Processors, 32 TAUs, and 16 Raster Operation Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The GeForce GT 640 DDR3 should in theory perform a lot faster than the GeForce GT 430 overall. (explain)
Texel RateThe GeForce GT 640 DDR3 should be much (approximately 157%) better at texture filtering than the GeForce GT 430. (explain)
Pixel RateIf running with a high screen resolution is important to you, then the GeForce GT 640 DDR3 is the winner, 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: Bandwidth is the maximum amount of data (measured in megabytes per second) that can be moved past the external memory interface within a second. The number is worked out by multiplying the card's interface width by its memory clock speed. If it uses DDR type memory, the result should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the faster 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 processed per second. This number is worked out by multiplying the total texture units of the card by the core speed of the chip. The higher the texel rate, the better the video 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 amount of pixels the video card can possibly record to its local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on many other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.