GeForce GTX 660 vs Radeon HD 3850 X2

Intro

Compare those specs to the Radeon HD 3850 X2, which has a GPU core clock speed of 668 MHz, and 512 MB of GDDR3 memory running at 828 MHz through a 256-bit bus. It also is comprised of 320(64x5) Stream Processors, 16 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Memory Bandwidth

Theoretically speaking, the GeForce GTX 660 should be 36% faster than the Radeon HD 3850 X2 in general, due to its higher data rate. (explain)

GeForce GTX 660		144192 MB/sec
Radeon HD 3850 X2		105984 MB/sec
	Difference: 38208 (36%)

Texel Rate

The GeForce GTX 660 is much (approximately 267%) more effective at AF than the Radeon HD 3850 X2. (explain)

GeForce GTX 660		78400 Mtexels/sec
Radeon HD 3850 X2		21376 Mtexels/sec
	Difference: 57024 (267%)

Pixel Rate

The GeForce GTX 660 is just a bit (approximately 10%) more effective at full screen anti-aliasing than the Radeon HD 3850 X2, and should be capable of handling higher resolutions without losing too much performance. (explain)

GeForce GTX 660		23520 Mpixels/sec
Radeon HD 3850 X2		21376 Mpixels/sec
	Difference: 2144 (10%)

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 largest amount of information (measured in megabytes per second) that can be moved past the external memory interface within a second. The number is worked out by multiplying the interface width by its memory clock speed. If it uses DDR memory, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed in one second. This figure is worked out 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 most pixels that the graphics card could possibly write to its local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.