GeForce GTX 660 vs Radeon HD 3870 512MB

Intro

Compare those specs to the Radeon HD 3870 512MB, which comes with a GPU core clock speed of 775 MHz, and 512 MB of GDDR3 RAM set to run at 900 MHz through a 256-bit bus. It also features 320(64x5) Stream Processors, 16 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3870 512MB		106 Watts
GeForce GTX 660		140 Watts
	Difference: 34 Watts (32%)

Memory Bandwidth

In theory, the GeForce GTX 660 should perform quite a bit faster than the Radeon HD 3870 512MB in general. (explain)

GeForce GTX 660		144192 MB/sec
Radeon HD 3870 512MB		57600 MB/sec
	Difference: 86592 (150%)

Texel Rate

The GeForce GTX 660 will be a lot (approximately 532%) faster with regards to anisotropic filtering than the Radeon HD 3870 512MB. (explain)

GeForce GTX 660		78400 Mtexels/sec
Radeon HD 3870 512MB		12400 Mtexels/sec
	Difference: 66000 (532%)

Pixel Rate

The GeForce GTX 660 will be a lot (more or less 90%) better at full screen anti-aliasing than the Radeon HD 3870 512MB, and also capable of handling higher resolutions while still performing well. (explain)

GeForce GTX 660		23520 Mpixels/sec
Radeon HD 3870 512MB		12400 Mpixels/sec
	Difference: 11120 (90%)

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 data (counted in MB per second) that can be transferred over the external memory interface in one second. It is calculated by multiplying the bus width by its memory clock speed. In the case of DDR type RAM, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels the video card could possibly write to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.