GeForce GT 640 DDR3 vs Geforce GTX 680

Intro

Compare all that to the Geforce GTX 680, which comes with core speeds of 1006 MHz on the GPU, and 1502 MHz on the 2048 MB of GDDR5 RAM. It features 1536 SPUs along with 128 TAUs and 32 Rasterization Operator 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

As far as performance goes, the Geforce GTX 680 should in theory be quite a bit better 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 should be much (more or less 347%) better at 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 using a high screen resolution is important to you, then the Geforce GTX 680 is the winner, 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: Bandwidth is the max amount of data (in units of 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 speed. If it uses DDR memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster 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 can be applied in one second. This number is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The higher the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the most pixels the graphics card could possibly record to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the number of Render Output Units by the the core clock speed. 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 rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.