Compare any two graphics cards:
GeForce GT 640 DDR3 vs GeForce GTX 260
IntroThe GeForce GT 640 DDR3 features a core clock frequency of 900 MHz and a DDR3 memory frequency of 1782 MHz. It also makes use of a 128-bit bus, and makes use of a 28 nm design. It features 384 SPUs, 32 TAUs, and 16 Raster Operation Units.
Compare those specifications to the GeForce GTX 260, which has core speeds of 576 MHz on the GPU, and 999 MHz on the 896 MB of GDDR3 memory. It features 192 SPUs along with 64 TAUs and 28 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the GeForce GTX 260 should be a lot faster than the GeForce GT 640 DDR3 overall. (explain)
Texel RateThe GeForce GTX 260 should be a lot (more or less 28%) better at AF than the GeForce GT 640 DDR3. (explain)
Pixel RateThe GeForce GTX 260 is a bit (more or less 12%) more effective at AA than the GeForce GT 640 DDR3, and capable of handling higher screen resolutions without slowing down too much. (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.
Price ComparisonPlease note that the price comparisons are based on search keywords, and might not be the exact same card listed on this page. We have no control over the accuracy of their search results.
Memory Bandwidth: Bandwidth is the largest amount of information (measured in MB per second) that can be moved across the external memory interface within a second. It is worked out by multiplying the card's bus width by the speed of its memory. If it uses DDR type memory, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed per second. This is worked out by multiplying the total number of texture units by the core clock speed of the chip. The better this number, 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 number of pixels the graphics card can possibly write to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.