GeForce 8800 GTS (G92) 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 RAM works at a frequency of 1782 MHz on this model. It features 384 SPUs as well as 32 TAUs and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
GeForce 8800 GTS (G92)		135 Watts
	Difference: 70 Watts (108%)

Memory Bandwidth

In theory, the GeForce 8800 GTS (G92) should be a bit faster than the GeForce GT 640 DDR3 overall. (explain)

GeForce 8800 GTS (G92)		62080 MB/sec
GeForce GT 640 DDR3		57024 MB/sec
	Difference: 5056 (9%)

Texel Rate

The GeForce 8800 GTS (G92) is quite a bit (more or less 44%) faster with regards to texture filtering than the GeForce GT 640 DDR3. (explain)

GeForce 8800 GTS (G92)		41600 Mtexels/sec
GeForce GT 640 DDR3		28800 Mtexels/sec
	Difference: 12800 (44%)

Pixel Rate

The GeForce GT 640 DDR3 is quite a bit (approximately 38%) more effective at anti-aliasing than the GeForce 8800 GTS (G92), and also will be capable of handling higher resolutions without losing too much performance. (explain)

GeForce GT 640 DDR3		14400 Mpixels/sec
GeForce 8800 GTS (G92)		10400 Mpixels/sec
	Difference: 4000 (38%)

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 largest amount of information (measured in megabytes per second) that can be transferred across the external memory interface within a second. The number is worked out by multiplying the card's interface width by its memory speed. In the case of DDR type RAM, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are 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 video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

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