GeForce GTX 660 Ti vs Radeon HD 4850 X2 1GB

Intro

Compare that to the Radeon HD 4850 X2 1GB, which has clock speeds of 625 MHz on the GPU, and 993 MHz on the 1024 MB of GDDR3 RAM. It features 800(160x5) SPUs along with 40 TAUs 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 4850 X2 1GB		250 Watts
	Difference: 100 Watts (67%)

Memory Bandwidth

In theory, the GeForce GTX 660 Ti will be 13% quicker than the Radeon HD 4850 X2 1GB in general, due to its higher bandwidth. (explain)

GeForce GTX 660 Ti		144000 MB/sec
Radeon HD 4850 X2 1GB		127104 MB/sec
	Difference: 16896 (13%)

Texel Rate

The GeForce GTX 660 Ti will be a lot (approximately 105%) more effective at AF than the Radeon HD 4850 X2 1GB. (explain)

GeForce GTX 660 Ti		102480 Mtexels/sec
Radeon HD 4850 X2 1GB		50000 Mtexels/sec
	Difference: 52480 (105%)

Pixel Rate

The GeForce GTX 660 Ti should be a bit (approximately 10%) faster with regards to full screen anti-aliasing than the Radeon HD 4850 X2 1GB, and capable of handling higher screen resolutions better. (explain)

GeForce GTX 660 Ti		21960 Mpixels/sec
Radeon HD 4850 X2 1GB		20000 Mpixels/sec
	Difference: 1960 (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 max amount of data (in units of MB per second) that can be transferred across the external memory interface in a second. The number is calculated by multiplying the interface width by its memory speed. If the card has DDR memory, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed in one second. This figure is calculated by multiplying the total texture units of the card by the core clock speed of the chip. The better the texel rate, the better the video 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 most pixels the video card can possibly write to its local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.