GeForce 8800 GTS (G80) 320MB vs GeForce GT 640 DDR3

Intro

Compare those specifications to the GeForce GT 640 DDR3, which features GPU clock speed of 900 MHz, and 2048 MB of DDR3 RAM running at 1782 MHz through a 128-bit bus. It also is made up of 384 Stream Processors, 32 Texture Address Units, 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 (G80) 320MB		143 Watts
	Difference: 78 Watts (120%)

Memory Bandwidth

Performance-wise, the GeForce 8800 GTS (G80) 320MB should in theory be a small bit superior to the GeForce GT 640 DDR3 overall. (explain)

GeForce 8800 GTS (G80) 320MB		63360 MB/sec
GeForce GT 640 DDR3		57024 MB/sec
	Difference: 6336 (11%)

Texel Rate

The GeForce GT 640 DDR3 should be a small bit (about 17%) faster with regards to AF than the GeForce 8800 GTS (G80) 320MB. (explain)

GeForce GT 640 DDR3		28800 Mtexels/sec
GeForce 8800 GTS (G80) 320MB		24624 Mtexels/sec
	Difference: 4176 (17%)

Pixel Rate

If running with a high screen resolution is important to you, then the GeForce GT 640 DDR3 is superior to the GeForce 8800 GTS (G80) 320MB, by far. (explain)

GeForce GT 640 DDR3		14400 Mpixels/sec
GeForce 8800 GTS (G80) 320MB		10260 Mpixels/sec
	Difference: 4140 (40%)

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 (counted in MB per second) that can be moved past the external memory interface in a second. It is calculated by multiplying the bus width by the speed of its memory. If the card has DDR type memory, the result should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed in one second. This figure is worked out by multiplying the total number of texture units by the core clock speed of the chip. The higher this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly write to the local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.