GeForce 9800 GX2 vs GeForce GTX 660 Ti

Intro

Compare those specifications to the GeForce GTX 660 Ti, which comes with a GPU core clock speed of 915 MHz, and 2048 MB of GDDR5 RAM set to run at 1500 MHz through a 192-bit bus. It also is made up of 1344 SPUs, 112 Texture Address Units, and 24 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 660 Ti		150 Watts
GeForce 9800 GX2		197 Watts
	Difference: 47 Watts (31%)

Memory Bandwidth

Theoretically speaking, the GeForce GTX 660 Ti should be 13% faster than the GeForce 9800 GX2 overall, because of its greater bandwidth. (explain)

GeForce GTX 660 Ti		144000 MB/sec
GeForce 9800 GX2		128000 MB/sec
	Difference: 16000 (13%)

Texel Rate

The GeForce GTX 660 Ti is quite a bit (more or less 33%) more effective at texture filtering than the GeForce 9800 GX2. (explain)

GeForce GTX 660 Ti		102480 Mtexels/sec
GeForce 9800 GX2		76800 Mtexels/sec
	Difference: 25680 (33%)

Pixel Rate

The GeForce GTX 660 Ti will be just a bit (about 14%) better at anti-aliasing than the GeForce 9800 GX2, and should be capable of handling higher resolutions while still performing well. (explain)

GeForce GTX 660 Ti		21960 Mpixels/sec
GeForce 9800 GX2		19200 Mpixels/sec
	Difference: 2760 (14%)

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 (in units of MB per second) that can be transferred past the external memory interface within a second. It's worked out by multiplying the card's interface width by its memory clock speed. If it uses DDR type memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied per second. This figure is calculated by multiplying the total texture units by the core clock 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 per second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly write to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.