GeForce GT 640 DDR3 vs Geforce GTX 680

Intro

Compare all of that to the Geforce GTX 680, which features a GPU core clock speed of 1006 MHz, and 2048 MB of GDDR5 RAM set to run at 1502 MHz through a 256-bit bus. It also features 1536 Stream Processors, 128 Texture Address Units, and 32 Raster Operation Units.

Display Graphs

Hide Graphs

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 680		7650 points
GeForce GT 640 DDR3		1560 points
	Difference: 6090 (390%)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
Geforce GTX 680		195 Watts
	Difference: 130 Watts (200%)

Memory Bandwidth

The Geforce GTX 680 should theoretically be much faster than the GeForce GT 640 DDR3 in general. (explain)

Geforce GTX 680		192256 MB/sec
GeForce GT 640 DDR3		57024 MB/sec
	Difference: 135232 (237%)

Texel Rate

The Geforce GTX 680 will be quite a bit (about 347%) faster with regards to texture filtering than the GeForce GT 640 DDR3. (explain)

Geforce GTX 680		128768 Mtexels/sec
GeForce GT 640 DDR3		28800 Mtexels/sec
	Difference: 99968 (347%)

Pixel Rate

If running with lots of anti-aliasing is important to you, then the Geforce GTX 680 is superior to the GeForce GT 640 DDR3, by far. (explain)

Geforce GTX 680		32192 Mpixels/sec
GeForce GT 640 DDR3		14400 Mpixels/sec
	Difference: 17792 (124%)

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 megabytes per second) that can be transported past 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 must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the most pixels that the graphics chip could possibly write to its 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 called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.