GeForce 8600 GT 512MB DDR2 vs GeForce GT 640 DDR3

Intro

Compare that 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 frequency of 1782 MHz on this specific model. It features 384 SPUs along with 32 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 8600 GT 512MB DDR2		47 Watts
GeForce GT 640 DDR3		65 Watts
	Difference: 18 Watts (38%)

Memory Bandwidth

The GeForce GT 640 DDR3, in theory, should be a lot faster than the GeForce 8600 GT 512MB DDR2 overall. (explain)

GeForce GT 640 DDR3		57024 MB/sec
GeForce 8600 GT 512MB DDR2		12800 MB/sec
	Difference: 44224 (346%)

Texel Rate

The GeForce GT 640 DDR3 will be much (about 233%) better at texture filtering than the GeForce 8600 GT 512MB DDR2. (explain)

GeForce GT 640 DDR3		28800 Mtexels/sec
GeForce 8600 GT 512MB DDR2		8640 Mtexels/sec
	Difference: 20160 (233%)

Pixel Rate

If using a high resolution is important to you, then the GeForce GT 640 DDR3 is superior to the GeForce 8600 GT 512MB DDR2, and very much so. (explain)

GeForce GT 640 DDR3		14400 Mpixels/sec
GeForce 8600 GT 512MB DDR2		4320 Mpixels/sec
	Difference: 10080 (233%)

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 megabytes per second) that can be moved over the external memory interface in a second. The number is calculated by multiplying the card's interface width by its memory clock speed. If it uses DDR type RAM, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed per second. This number is worked out by multiplying the total number of texture units by the core clock speed of the chip. The higher the texel rate, the better the graphics 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 the video card can possibly record to the local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the number of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.