Compare any two graphics cards:
GeForce GT 640 DDR3 vs GeForce GTX 460
IntroThe GeForce GT 640 DDR3 comes with a clock speed of 900 MHz and a DDR3 memory speed of 1782 MHz. It also makes use of a 128-bit memory bus, and makes use of a 28 nm design. It is comprised of 384 SPUs, 32 TAUs, and 16 ROPs.
Compare all that to the GeForce GTX 460, which makes use of a 40 nm design. nVidia has clocked the core frequency at 675 MHz. The GDDR5 memory runs at a speed of 900 MHz on this specific model. It features 336 SPUs as well as 56 TAUs and 24 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the GeForce GTX 460 will be 52% faster than the GeForce GT 640 DDR3 overall, because of its greater data rate. (explain)
Texel RateThe GeForce GTX 460 should be much (approximately 31%) faster with regards to texture filtering than the GeForce GT 640 DDR3. (explain)
Pixel RateThe GeForce GTX 460 will be a bit (more or less 13%) more effective at full screen anti-aliasing than the GeForce GT 640 DDR3, and will be capable of handling higher resolutions better. (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: Memory bandwidth is the max amount of information (counted in MB per second) that can be moved across the external memory interface within a second. It is calculated by multiplying the interface width by the speed of its memory. If it uses DDR memory, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the card's 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 amount of texture map elements (texels) that are processed in one second. This number is worked out by multiplying the total number of texture units of the card by the core speed of the chip. The higher the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.
Pixel Rate: Pixel rate is the most pixels that the graphics chip could possibly record to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the max fill rate.