GeForce GTX 660 vs Geforce GTX 680

Intro

The GeForce GTX 660 comes with a core clock frequency of 980 MHz and a GDDR5 memory frequency of 1502 MHz. It also uses a 192-bit memory bus, and makes use of a 28 nm design. It is made up of 960 SPUs, 80 TAUs, and 24 Raster Operation Units.

Compare all of that to the Geforce GTX 680, which has GPU core speed of 1006 MHz, and 2048 MB of GDDR5 memory set to run at 1502 MHz through a 256-bit bus. It also is made up of 1536 SPUs, 128 Texture Address Units, and 32 ROPs.

Price Comparison

Please note that the price comparisons are based on search keywords, and might not be the exact same card listed on this page. We have no control over the accuracy of their search results.

GeForce GTX 660 Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Geforce GTX 680 Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Specifications

Model	GeForce GTX 660	Geforce GTX 680
Manufacturer	nVidia	nVidia
Year	September 2012	March 2012
Code Name	GK106	GK104
Fab Process	28 nm	28 nm
Bus	PCIe 3.0 x16	PCIe 3.0 x16
Memory	2048 MB	2048 MB
Core Speed	980 MHz	1006 MHz
Shader Speed	980 MHz	1006 MHz
Memory Speed	1502 MHz (6008 MHz effective)	1502 MHz (6008 MHz effective)
Unified Shaders	960	1536
Texture Mapping Units	80	128
Render Output Units	24	32
Bus Type	GDDR5	GDDR5
Bus Width	192-bit	256-bit
DirectX Version	DirectX 11.1	DirectX 11.1
OpenGL Version	OpenGL 4.3	OpenGL 4.2
Power (Max TDP)	140 watts	195 watts
Shader Model	5.0	5.0
Bandwidth	144192 MB/sec	192256 MB/sec
Texel Rate	78400 Mtexels/sec	128768 Mtexels/sec
Pixel Rate	23520 Mpixels/sec	32192 Mpixels/sec

Memory Bandwidth: Memory bandwidth is the largest amount of information (in units of megabytes per second) that can be moved past the external memory interface within a second. It is calculated by multiplying the card's bus width by the speed of its memory. In the case of 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 are applied per second. This number is calculated by multiplying the total texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly record to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate also depends 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.