GeForce GT 640 DDR3 vs GeForce GTX 580

Intro

Compare all that to the GeForce GTX 580, which makes use of a 40 nm design. nVidia has set the core speed at 772 MHz. The GDDR5 RAM works at a frequency of 1002 MHz on this card. It features 512 SPUs as well as 64 TAUs and 48 Rasterization Operator Units.

Display Graphs

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Benchmarks

These are real-world performance benchmarks that were submitted by Hardware Compare users. The scores seen here are the average of all benchmarks submitted for each respective test and hardware.

3DMark Fire Strike Graphics Score

GeForce GTX 580		4956 points
GeForce GT 640 DDR3		1560 points
	Difference: 3396 (218%)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
GeForce GTX 580		244 Watts
	Difference: 179 Watts (275%)

Memory Bandwidth

In theory, the GeForce GTX 580 is 237% faster than the GeForce GT 640 DDR3 in general, due to its higher bandwidth. (explain)

GeForce GTX 580		192384 MB/sec
GeForce GT 640 DDR3		57024 MB/sec
	Difference: 135360 (237%)

Texel Rate

The GeForce GTX 580 will be quite a bit (approximately 72%) better at anisotropic filtering than the GeForce GT 640 DDR3. (explain)

GeForce GTX 580		49408 Mtexels/sec
GeForce GT 640 DDR3		28800 Mtexels/sec
	Difference: 20608 (72%)

Pixel Rate

The GeForce GTX 580 will be much (approximately 157%) better at AA than the GeForce GT 640 DDR3, and also capable of handling higher screen resolutions without losing too much performance. (explain)

GeForce GTX 580		37056 Mpixels/sec
GeForce GT 640 DDR3		14400 Mpixels/sec
	Difference: 22656 (157%)

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 transferred across the external memory interface in one second. It's worked out by multiplying the interface width by the speed of its memory. In the case of DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the bandwidth is, 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 applied per second. This figure is calculated by multiplying the total amount of texture units by the core speed of the chip. The better the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card could possibly record to the local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the amount of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.