GeForce 9800 GX2 vs GeForce GTX 660

Intro

Compare those specifications to the GeForce GTX 660, which has core clock speeds of 980 MHz on the GPU, and 1502 MHz on the 2048 MB of GDDR5 memory. It features 960 SPUs along with 80 TAUs and 24 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 660		140 Watts
GeForce 9800 GX2		197 Watts
	Difference: 57 Watts (41%)

Memory Bandwidth

The GeForce GTX 660, in theory, should be a bit faster than the GeForce 9800 GX2 overall. (explain)

GeForce GTX 660		144192 MB/sec
GeForce 9800 GX2		128000 MB/sec
	Difference: 16192 (13%)

Texel Rate

The GeForce GTX 660 is a bit (more or less 2%) more effective at texture filtering than the GeForce 9800 GX2. (explain)

GeForce GTX 660		78400 Mtexels/sec
GeForce 9800 GX2		76800 Mtexels/sec
	Difference: 1600 (2%)

Pixel Rate

The GeForce GTX 660 will be a lot (more or less 23%) better at full screen anti-aliasing than the GeForce 9800 GX2, and able to handle higher resolutions better. (explain)

GeForce GTX 660		23520 Mpixels/sec
GeForce 9800 GX2		19200 Mpixels/sec
	Difference: 4320 (23%)

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 maximum amount of data (in units of MB per second) that can be transferred across the external memory interface in a second. It is calculated by multiplying the bus width by the speed of its memory. In the case of DDR type RAM, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip can possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.