GeForce GTX 660 Ti vs Radeon HD 6950 2GB

Intro

Compare those specifications to the Radeon HD 6950 2GB, which has a clock speed of 800 MHz and a GDDR5 memory speed of 1250 MHz. It also makes use of a 256-bit bus, and makes use of a 40 nm design. It is made up of 1408 SPUs, 88 Texture Address Units, and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 660 Ti		150 Watts
Radeon HD 6950 2GB		200 Watts
	Difference: 50 Watts (33%)

Memory Bandwidth

In theory, the Radeon HD 6950 2GB should be 11% faster than the GeForce GTX 660 Ti in general, because of its greater data rate. (explain)

Radeon HD 6950 2GB		160000 MB/sec
GeForce GTX 660 Ti		144000 MB/sec
	Difference: 16000 (11%)

Texel Rate

The GeForce GTX 660 Ti will be a lot (more or less 46%) more effective at texture filtering than the Radeon HD 6950 2GB. (explain)

GeForce GTX 660 Ti		102480 Mtexels/sec
Radeon HD 6950 2GB		70400 Mtexels/sec
	Difference: 32080 (46%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon HD 6950 2GB is the winner, but only just. (explain)

Radeon HD 6950 2GB		25600 Mpixels/sec
GeForce GTX 660 Ti		21960 Mpixels/sec
	Difference: 3640 (17%)

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 MB per second) that can be transported over the external memory interface in one second. It is calculated by multiplying the interface width by the speed of its memory. If it uses DDR RAM, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly write to the local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called 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, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.