GeForce 9800 GX2 vs GeForce GTX 660

Intro

Compare that 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 RAM. It features 960 SPUs along with 80 Texture Address Units and 24 ROPs.

Display Graphs

Hide Graphs

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

Theoretically speaking, the GeForce GTX 660 should be 13% quicker than the GeForce 9800 GX2 overall, due to its greater bandwidth. (explain)

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

Texel Rate

The GeForce GTX 660 will be a small 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

If using high levels of AA is important to you, then the GeForce GTX 660 is the winner, by far. (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: Memory bandwidth is the max amount of information (measured in MB per second) that can be transported past the external memory interface within a second. It is worked out by multiplying the bus width by its memory speed. In the case of DDR type memory, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the most pixels the video card can possibly record to its local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.