GeForce GT 440 3GB vs GeForce GT 640 DDR3

Intro

Compare all that to the GeForce GT 640 DDR3, which features GPU core speed of 900 MHz, and 2048 MB of DDR3 memory set to run at 1782 MHz through a 128-bit bus. It also is comprised of 384 SPUs, 32 TAUs, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 440 3GB		56 Watts
GeForce GT 640 DDR3		65 Watts
	Difference: 9 Watts (16%)

Memory Bandwidth

Theoretically speaking, the GeForce GT 640 DDR3 is 32% faster than the GeForce GT 440 3GB in general, because of its higher bandwidth. (explain)

GeForce GT 640 DDR3		57024 MB/sec
GeForce GT 440 3GB		43200 MB/sec
	Difference: 13824 (32%)

Texel Rate

The GeForce GT 640 DDR3 will be quite a bit (more or less 102%) better at anisotropic filtering than the GeForce GT 440 3GB. (explain)

GeForce GT 640 DDR3		28800 Mtexels/sec
GeForce GT 440 3GB		14256 Mtexels/sec
	Difference: 14544 (102%)

Pixel Rate

The GeForce GT 640 DDR3 will be a little bit (approximately 1%) better at full screen anti-aliasing than the GeForce GT 440 3GB, and also will be capable of handling higher resolutions better. (explain)

GeForce GT 640 DDR3		14400 Mpixels/sec
GeForce GT 440 3GB		14256 Mpixels/sec
	Difference: 144 (1%)

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: Bandwidth is the largest amount of information (counted in MB per second) that can be moved across the external memory interface in a second. It's calculated by multiplying the card's interface width by its memory speed. If it uses DDR type RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher 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 applied in one second. This number is calculated by multiplying the total amount of texture units by the core clock speed of the chip. The better this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

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