Compare any two graphics cards:
GeForce GT 640 DDR3 vs GeForce GTX 650
IntroThe GeForce GT 640 DDR3 features clock speeds of 900 MHz on the GPU, and 1782 MHz on the 2048 MB of DDR3 memory. It features 384 SPUs along with 32 Texture Address Units and 16 ROPs.
Compare those specifications to the GeForce GTX 650, which features GPU clock speed of 1058 MHz, and 2048 MB of GDDR5 RAM running at 1250 MHz through a 128-bit bus. It also is comprised of 384 Stream Processors, 32 Texture Address Units, and 16 Raster Operation Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the GeForce GTX 650 should be much faster than the GeForce GT 640 DDR3 in general. (explain)
Texel RateThe GeForce GTX 650 is a little bit (more or less 18%) faster with regards to AF than the GeForce GT 640 DDR3. (explain)
Pixel RateThe GeForce GTX 650 is just a bit (approximately 18%) more effective at FSAA than the GeForce GT 640 DDR3, and also will be capable of handling higher screen 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.
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 (measured in megabytes per second) that can be transported past the external memory interface in one second. The number is calculated by multiplying the interface width by its memory clock speed. In the case of DDR type RAM, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This number is worked out by multiplying the total amount of texture units of the card by the core speed of the chip. The better the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.
Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly write to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of colour ROPs 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 output rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.