GeForce GTX 660 vs Radeon HD 3870 X2 1GB

Intro

Compare that to the Radeon HD 3870 X2 1GB, which makes use of a 55 nm design. AMD has set the core speed at 825 MHz. The GDDR4 RAM is set to run at a speed of 1126 MHz on this card. It features 320(64x5) SPUs along with 16 TAUs and 16 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

Theoretically, the GeForce GTX 660 should be a little bit faster than the Radeon HD 3870 X2 1GB overall. (explain)

GeForce GTX 660		144192 MB/sec
Radeon HD 3870 X2 1GB		144128 MB/sec
	Difference: 64 (0%)

Texel Rate

The GeForce GTX 660 is quite a bit (about 197%) more effective at texture filtering than the Radeon HD 3870 X2 1GB. (explain)

GeForce GTX 660		78400 Mtexels/sec
Radeon HD 3870 X2 1GB		26400 Mtexels/sec
	Difference: 52000 (197%)

Pixel Rate

The Radeon HD 3870 X2 1GB will be a little bit (about 12%) better at anti-aliasing than the GeForce GTX 660, and also will be capable of handling higher resolutions without slowing down too much. (explain)

Radeon HD 3870 X2 1GB		26400 Mpixels/sec
GeForce GTX 660		23520 Mpixels/sec
	Difference: 2880 (12%)

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.

One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the largest amount of data (counted in MB per second) that can be transported over the external memory interface in one second. It's worked out by multiplying the interface width by its memory speed. In the case of DDR type memory, the result should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed in one second. This figure 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 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 that the graphics card could possibly record to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel 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 ability to reach the maximum fill rate.