GeForce GT 240 GDDR5 vs GeForce GT 640 DDR3

Intro

Compare those specifications to the GeForce GT 640 DDR3, which uses a 28 nm design. nVidia has set the core frequency at 900 MHz. The DDR3 memory is set to run at a speed of 1782 MHz on this specific card. It features 384 SPUs along with 32 Texture Address Units and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
GeForce GT 240 GDDR5		70 Watts
	Difference: 5 Watts (8%)

Memory Bandwidth

The GeForce GT 640 DDR3, in theory, should perform a small bit faster than the GeForce GT 240 GDDR5 in general. (explain)

GeForce GT 640 DDR3		57024 MB/sec
GeForce GT 240 GDDR5		54400 MB/sec
	Difference: 2624 (5%)

Texel Rate

The GeForce GT 640 DDR3 should be a lot (more or less 64%) more effective at anisotropic filtering than the GeForce GT 240 GDDR5. (explain)

GeForce GT 640 DDR3		28800 Mtexels/sec
GeForce GT 240 GDDR5		17600 Mtexels/sec
	Difference: 11200 (64%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the GeForce GT 640 DDR3 is superior to the GeForce GT 240 GDDR5, by far. (explain)

GeForce GT 640 DDR3		14400 Mpixels/sec
GeForce GT 240 GDDR5		4400 Mpixels/sec
	Difference: 10000 (227%)

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 maximum amount of information (in units of megabytes per second) that can be moved past the external memory interface within a second. It's worked out by multiplying the card's interface width by the speed of its memory. If the card has DDR type memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied per second. This is worked out by multiplying the total texture units 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 a second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip can possibly write to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.