GeForce GTX 660 Ti vs Radeon HD 4870 X2

Intro

Compare all of that to the Radeon HD 4870 X2, which comes with a core clock frequency of 750 MHz and a GDDR5 memory frequency of 900 MHz. It also makes use of a 256-bit memory bus, and uses a 55 nm design. It 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 660 Ti		150 Watts
Radeon HD 4870 X2		350 Watts
	Difference: 200 Watts (133%)

Memory Bandwidth

As far as performance goes, the Radeon HD 4870 X2 should in theory be quite a bit better than 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 will be much (approximately 71%) better 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 should be a little bit (more or less 9%) more effective at anti-aliasing than the GeForce GTX 660 Ti, and also should be capable of handling higher resolutions while still performing well. (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: Memory bandwidth is the max amount of data (in units of MB per second) that can be transported across the external memory interface in a second. It is calculated by multiplying the interface width by its memory speed. If the card has DDR RAM, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied in one second. This is calculated by multiplying the total texture units by the core speed of the chip. The better this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly record to the local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.