GeForce GTX 660 Ti vs Radeon HD 4870 X2

Intro

Compare all of that to the Radeon HD 4870 X2, which comes with clock speeds of 750 MHz on the GPU, and 900 MHz on the 1024 MB of GDDR5 memory. It features 800(160x5) SPUs along with 40 TAUs and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 660 Ti		150 Watts
Radeon HD 4870 X2		350 Watts
	Difference: 200 Watts (133%)

Memory Bandwidth

Performance-wise, the Radeon HD 4870 X2 should theoretically be a lot superior to the GeForce GTX 660 Ti in general. (explain)

Radeon HD 4870 X2		230400 MB/sec
GeForce GTX 660 Ti		144000 MB/sec
	Difference: 86400 (60%)

Texel Rate

The GeForce GTX 660 Ti is quite a bit (approximately 71%) more effective at texture filtering than the Radeon HD 4870 X2. (explain)

GeForce GTX 660 Ti		102480 Mtexels/sec
Radeon HD 4870 X2		60000 Mtexels/sec
	Difference: 42480 (71%)

Pixel Rate

The Radeon HD 4870 X2 will be a little bit (more or less 9%) better at FSAA than the GeForce GTX 660 Ti, and should be capable of handling higher screen resolutions more effectively. (explain)

Radeon HD 4870 X2		24000 Mpixels/sec
GeForce GTX 660 Ti		21960 Mpixels/sec
	Difference: 2040 (9%)

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 across the external memory interface in a second. It's calculated by multiplying the card's bus width by its memory speed. If the card has DDR RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the card's 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 are processed in one second. This number is calculated by multiplying the total amount of texture units by the core clock speed of the chip. The better the texel rate, 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 number of pixels that the graphics card can possibly write to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate also depends on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.