GeForce 9400 GT 256MB vs GeForce 9800 GX2

Intro

Compare all that to the GeForce 9800 GX2, which features a core clock speed 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 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 9400 GT 256MB		50 Watts
GeForce 9800 GX2		197 Watts
	Difference: 147 Watts (294%)

Memory Bandwidth

Performance-wise, the GeForce 9800 GX2 should in theory be much better than the GeForce 9400 GT 256MB in general. (explain)

GeForce 9800 GX2		128000 MB/sec
GeForce 9400 GT 256MB		12800 MB/sec
	Difference: 115200 (900%)

Texel Rate

The GeForce 9800 GX2 will be much (more or less 1645%) faster with regards to anisotropic filtering than the GeForce 9400 GT 256MB. (explain)

GeForce 9800 GX2		76800 Mtexels/sec
GeForce 9400 GT 256MB		4400 Mtexels/sec
	Difference: 72400 (1645%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the GeForce 9800 GX2 is the winner, and very much so. (explain)

GeForce 9800 GX2		19200 Mpixels/sec
GeForce 9400 GT 256MB		2200 Mpixels/sec
	Difference: 17000 (773%)

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 data (counted in megabytes per second) that can be transported over the external memory interface in a second. The number is worked out by multiplying the card's bus width by its memory clock speed. If the card has DDR memory, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed in one second. This number is calculated by multiplying the total number of texture units by the core clock speed of the chip. The higher this number, 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 maximum amount of pixels the video card can possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Raster Operations Pipelines 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 output rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.