GeForce 9800 GTX vs GeForce 9800 GX2

Intro

Compare those specifications to the GeForce 9800 GX2, which has a clock frequency of 600 MHz and a GDDR3 memory frequency of 1000 MHz. It also features a 256-bit bus, and uses a 65 nm design. It features 128 SPUs, 64 TAUs, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

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

Memory Bandwidth

The GeForce 9800 GX2 should theoretically be much faster than the GeForce 9800 GTX overall. (explain)

GeForce 9800 GX2		128000 MB/sec
GeForce 9800 GTX		70400 MB/sec
	Difference: 57600 (82%)

Texel Rate

The GeForce 9800 GX2 is quite a bit (approximately 78%) more effective at texture filtering than the GeForce 9800 GTX. (explain)

GeForce 9800 GX2		76800 Mtexels/sec
GeForce 9800 GTX		43200 Mtexels/sec
	Difference: 33600 (78%)

Pixel Rate

If running with high levels of AA is important to you, then the GeForce 9800 GX2 is superior to the GeForce 9800 GTX, by a large margin. (explain)

GeForce 9800 GX2		19200 Mpixels/sec
GeForce 9800 GTX		10800 Mpixels/sec
	Difference: 8400 (78%)

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 (counted in MB per second) that can be transported across the external memory interface in a second. It's calculated by multiplying the bus width by the speed of its memory. If it uses DDR type memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied per second. This figure is worked out by multiplying the total amount of texture units by the core speed of the chip. The better the texel rate, the better the graphics 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 most pixels the graphics card could possibly record to the 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 card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the max fill rate.