GeForce GTX 660 Ti vs Radeon HD 7950

Intro

The GeForce GTX 660 Ti has a clock frequency of 915 MHz and a GDDR5 memory frequency of 1500 MHz. It also features a 192-bit bus, and makes use of a 28 nm design. It is comprised of 1344 SPUs, 112 Texture Address Units, and 24 Raster Operation Units.

Compare those specs to the Radeon HD 7950, which uses a 28 nm design. ATi has set the core speed at 800 MHz. The GDDR5 memory is set to run at a speed of 1250 MHz on this card. It features 1792 SPUs as well as 112 TAUs and 32 Rasterization Operator Units.

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 Ti Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Radeon HD 7950 Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Specifications

Model	GeForce GTX 660 Ti	Radeon HD 7950
Manufacturer	nVidia	ATi
Year	August 2012	January 2012
Code Name	GK104	Tahiti Pro
Fab Process	28 nm	28 nm
Bus	PCIe 3.0 x16	PCIe 3.0 x16
Memory	2048 MB	1536 MB
Core Speed	915 MHz	800 MHz
Shader Speed	915 MHz	(N/A) MHz
Memory Speed	1500 MHz (6000 MHz effective)	1250 MHz (5000 MHz effective)
Unified Shaders	1344	1792
Texture Mapping Units	112	112
Render Output Units	24	32
Bus Type	GDDR5	GDDR5
Bus Width	192-bit	384-bit
DirectX Version	DirectX 11.1	DirectX 11.1
OpenGL Version	OpenGL 4.3	OpenGL 4.2
Power (Max TDP)	150 watts	200 watts
Shader Model	5.0	5.0
Bandwidth	144000 MB/sec	240000 MB/sec
Texel Rate	102480 Mtexels/sec	89600 Mtexels/sec
Pixel Rate	21960 Mpixels/sec	25600 Mpixels/sec

Memory Bandwidth: Memory bandwidth is the max amount of data (measured in MB per second) that can be transferred past the external memory interface within a second. It is worked out by multiplying the card's bus width by its memory speed. In the case of DDR RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the most pixels that the graphics chip could possibly write to the local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the max fill rate.