GeForce GTX 660 Ti vs Radeon HD 4850 X2 512MB

Intro

Compare all of that to the Radeon HD 4850 X2 512MB, which comes with a core clock frequency of 625 MHz and a GDDR3 memory speed of 993 MHz. It also features 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 4850 X2 512MB		250 Watts
	Difference: 100 Watts (67%)

Memory Bandwidth

Theoretically, the GeForce GTX 660 Ti should be just a bit faster than the Radeon HD 4850 X2 512MB in general. (explain)

GeForce GTX 660 Ti		144000 MB/sec
Radeon HD 4850 X2 512MB		127104 MB/sec
	Difference: 16896 (13%)

Texel Rate

The GeForce GTX 660 Ti should be a lot (approximately 105%) better at anisotropic filtering than the Radeon HD 4850 X2 512MB. (explain)

GeForce GTX 660 Ti		102480 Mtexels/sec
Radeon HD 4850 X2 512MB		50000 Mtexels/sec
	Difference: 52480 (105%)

Pixel Rate

The GeForce GTX 660 Ti should be just a bit (about 10%) more effective at full screen anti-aliasing than the Radeon HD 4850 X2 512MB, and also will be able to handle higher resolutions without slowing down too much. (explain)

GeForce GTX 660 Ti		21960 Mpixels/sec
Radeon HD 4850 X2 512MB		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: Memory bandwidth is the largest amount of data (measured in MB per second) that can be transferred past the external memory interface within a second. It is calculated by multiplying the card's bus width by the speed of its memory. If the card has DDR memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the faster 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 applied per second. This is worked out by multiplying the total texture units of the card by the core speed of the chip. The better this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly write to its local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill 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.