Geforce GTX 680 vs Radeon HD 4870 X2

Intro

Compare that to the Radeon HD 4870 X2, which comes with GPU core speed of 750 MHz, and 1024 MB of GDDR5 RAM running at 900 MHz through a 256-bit bus. It also is comprised of 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Geforce GTX 680		195 Watts
Radeon HD 4870 X2		350 Watts
	Difference: 155 Watts (79%)

Memory Bandwidth

Theoretically, the Radeon HD 4870 X2 should be a bit faster than the Geforce GTX 680 overall. (explain)

Radeon HD 4870 X2		230400 MB/sec
Geforce GTX 680		192256 MB/sec
	Difference: 38144 (20%)

Texel Rate

The Geforce GTX 680 is much (about 115%) more effective at anisotropic filtering than the Radeon HD 4870 X2. (explain)

Geforce GTX 680		128768 Mtexels/sec
Radeon HD 4870 X2		60000 Mtexels/sec
	Difference: 68768 (115%)

Pixel Rate

The Geforce GTX 680 is quite a bit (about 34%) better at FSAA than the Radeon HD 4870 X2, and capable of handling higher resolutions more effectively. (explain)

Geforce GTX 680		32192 Mpixels/sec
Radeon HD 4870 X2		24000 Mpixels/sec
	Difference: 8192 (34%)

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 information (measured in megabytes per second) that can be transferred over the external memory interface in a second. It is calculated by multiplying the card's bus width by its memory speed. If it uses DDR memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied per second. This figure is worked out by multiplying the total number of texture units by the core clock speed of the chip. The better the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly write to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the number of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel 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.