GeForce GT 640 DDR3 vs GeForce GTX 460 SE

Intro

Compare that to the GeForce GTX 460 SE, which comes with a GPU core clock speed of 650 MHz, and 1024 MB of GDDR5 memory running at 850 MHz through a 256-bit bus. It also features 288 SPUs, 48 TAUs, and 32 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
GeForce GTX 460 SE		150 Watts
	Difference: 85 Watts (131%)

Memory Bandwidth

Performance-wise, the GeForce GTX 460 SE should theoretically be a lot superior to the GeForce GT 640 DDR3 in general. (explain)

GeForce GTX 460 SE		108800 MB/sec
GeForce GT 640 DDR3		57024 MB/sec
	Difference: 51776 (91%)

Texel Rate

The GeForce GTX 460 SE should be a bit (more or less 8%) faster with regards to texture filtering than the GeForce GT 640 DDR3. (explain)

GeForce GTX 460 SE		31200 Mtexels/sec
GeForce GT 640 DDR3		28800 Mtexels/sec
	Difference: 2400 (8%)

Pixel Rate

If using high levels of AA is important to you, then the GeForce GTX 460 SE is a better choice, by a large margin. (explain)

GeForce GTX 460 SE		20800 Mpixels/sec
GeForce GT 640 DDR3		14400 Mpixels/sec
	Difference: 6400 (44%)

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 Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the max amount of data (counted in megabytes per second) that can be transferred across the external memory interface within a second. The number is calculated by multiplying the card's bus width by its memory clock speed. In the case of DDR type RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster 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 can be processed per second. This figure is worked out by multiplying the total number of texture units by the core speed of the chip. The better this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card could possibly record to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the amount of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.