Compare any two graphics cards:
GeForce GT 640 DDR3 vs GeForce GTX 460
IntroThe GeForce GT 640 DDR3 comes with core speeds of 900 MHz on the GPU, and 1782 MHz on the 2048 MB of DDR3 RAM. It features 384 SPUs as well as 32 TAUs and 16 Rasterization Operator Units.
Compare those specs to the GeForce GTX 460, which comes with a GPU core clock speed of 675 MHz, and 768 MB of GDDR5 RAM running at 900 MHz through a 192-bit bus. It also features 336 Stream Processors, 56 Texture Address Units, and 24 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the GeForce GTX 460 will be 52% quicker than the GeForce GT 640 DDR3 in general, due to its higher data rate. (explain)
Texel RateThe GeForce GTX 460 is much (about 31%) more effective at AF than the GeForce GT 640 DDR3. (explain)
Pixel RateThe GeForce GTX 460 should be just a bit (about 13%) more effective at FSAA than the GeForce GT 640 DDR3, and 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 (counted in MB per second) that can be transported over the external memory interface within a second. The number is worked out by multiplying the card's interface width by its memory speed. If it uses DDR RAM, it must 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 high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed in one second. This is calculated by multiplying the total texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could 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 ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.