GeForce GTX 660 vs Radeon HD 3870 512MB

Intro

Compare all of that to the Radeon HD 3870 512MB, which comes with a clock frequency of 775 MHz and a GDDR3 memory speed of 900 MHz. It also makes use of a 256-bit bus, and uses a 55 nm design. It is comprised of 320(64x5) SPUs, 16 TAUs, and 16 ROPs.

Display Graphs

Hide Graphs

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

Theoretically speaking, the GeForce GTX 660 should be 150% faster than the Radeon HD 3870 512MB in general, due to its higher bandwidth. (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 quite a bit (approximately 532%) more effective at 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

If running with a high resolution is important to you, then the GeForce GTX 660 is a better choice, by a large margin. (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: Bandwidth is the largest amount of data (measured in megabytes per second) that can be moved over the external memory interface in one second. It's worked out by multiplying the card's interface width by its memory speed. If the card has DDR memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, the faster 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 amount of texture map elements (texels) that are processed per second. This figure is calculated by multiplying the total number of texture units by the core clock speed of the chip. The higher this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly record to the local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of Render Output Units by the the card's 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 fill rate is also dependant on lots of 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.