GeForce GTX 660 vs Radeon HD 3870 X2 1GB

Intro

Compare all that to the Radeon HD 3870 X2 1GB, which features GPU clock speed of 825 MHz, and 1024 MB of GDDR4 memory running at 1126 MHz through a 256-bit bus. It also features 320(64x5) SPUs, 16 TAUs, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

Theoretically, the GeForce GTX 660 should perform 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 a lot (about 197%) more effective at AF 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 small bit (approximately 12%) faster with regards to full screen anti-aliasing than the GeForce GTX 660, and also capable of handling higher screen resolutions while still performing well. (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: Bandwidth is the maximum amount of data (counted in MB per second) that can be moved over the external memory interface within a second. It's worked out by multiplying the interface width by its memory speed. In the case of DDR RAM, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the faster 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 calculated by multiplying the total number of texture units by the core speed of the chip. The higher this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate is also dependant on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the max fill rate.