Geforce GTX 690 vs Radeon HD 3870 X2 512MB

Intro

Compare those specs to the Radeon HD 3870 X2 512MB, which uses a 55 nm design. AMD has set the core speed at 825 MHz. The GDDR3 memory is set to run at a speed of 900 MHz on this specific model. It features 320(64x5) SPUs along with 16 Texture Address Units and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Memory Bandwidth

In theory, the Geforce GTX 690 is 234% faster than the Radeon HD 3870 X2 512MB overall, because of its greater data rate. (explain)

Geforce GTX 690		384512 MB/sec
Radeon HD 3870 X2 512MB		115200 MB/sec
	Difference: 269312 (234%)

Texel Rate

The Geforce GTX 690 will be quite a bit (about 787%) more effective at anisotropic filtering than the Radeon HD 3870 X2 512MB. (explain)

Geforce GTX 690		234240 Mtexels/sec
Radeon HD 3870 X2 512MB		26400 Mtexels/sec
	Difference: 207840 (787%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Geforce GTX 690 is superior to the Radeon HD 3870 X2 512MB, by a large margin. (explain)

Geforce GTX 690		58560 Mpixels/sec
Radeon HD 3870 X2 512MB		26400 Mpixels/sec
	Difference: 32160 (122%)

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 data (in units of MB per second) that can be transferred over the external memory interface in one second. It's calculated by multiplying the card's bus width by its memory speed. In the case of DDR type RAM, it must be multiplied by 2 again. If it uses 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 high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed per second. This number is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher this number, the better the 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 write to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the number of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.