Compare any two graphics cards:
GeForce GT 640 DDR3 vs GeForce GTX 260
IntroThe GeForce GT 640 DDR3 has a core clock frequency of 900 MHz and a DDR3 memory frequency of 1782 MHz. It also uses a 128-bit bus, and makes use of a 28 nm design. It features 384 SPUs, 32 Texture Address Units, and 16 Raster Operation Units.
Compare those specs to the GeForce GTX 260, which comes with GPU core speed of 576 MHz, and 896 MB of GDDR3 RAM set to run at 999 MHz through a 448-bit bus. It also is made up of 192 Stream Processors, 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 will be much (more or less 28%) better at AF than the GeForce GT 640 DDR3. (explain)
Pixel RateIf running with lots of anti-aliasing is important to you, then the GeForce GTX 260 is a better choice, but only just. (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 maximum amount of data (in units of megabytes per second) that can be moved across the external memory interface in one second. The number is calculated by multiplying the interface width by its memory speed. If it uses DDR RAM, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the 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 are processed per second. This is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The higher this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly write to its local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.