Compare any two graphics cards:
GeForce GT 640 DDR3 vs GeForce GTX 580 3GB
IntroThe GeForce GT 640 DDR3 comes with a GPU core speed of 900 MHz, and the 2048 MB of DDR3 RAM is set to run at 1782 MHz through a 128-bit bus. It also features 384 Stream Processors, 32 TAUs, and 16 ROPs.
Compare those specs to the GeForce GTX 580 3GB, which makes use of a 40 nm design. nVidia has clocked the core speed at 772 MHz. The GDDR5 RAM runs at a speed of 1002 MHz on this particular card. It features 512 SPUs along with 64 Texture Address Units and 48 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the GeForce GTX 580 3GB should be quite a bit faster than the GeForce GT 640 DDR3 in general. (explain)
Texel RateThe GeForce GTX 580 3GB will be quite a bit (more or less 72%) faster with regards to anisotropic filtering than the GeForce GT 640 DDR3. (explain)
Pixel RateIf running with a high screen resolution is important to you, then the GeForce GTX 580 3GB is a better choice, 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.
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: Memory bandwidth is the largest amount of information (counted in megabytes per second) that can be transported across the external memory interface in one second. It's calculated by multiplying the card's interface width by its memory clock speed. If it uses DDR memory, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the better 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 applied per second. This figure is calculated by multiplying the total amount of texture units of the card by the core clock speed of the chip. The better the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly write to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the number of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.