GeForce 9400 GT 256MB vs GeForce 9800 GX2

Intro

Compare all that to the GeForce 9800 GX2, which features a clock frequency of 600 MHz and a GDDR3 memory speed of 1000 MHz. It also uses a 256-bit memory bus, and makes use of a 65 nm design. It features 128 SPUs, 64 Texture Address Units, 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

As far as performance goes, the GeForce 9800 GX2 should in theory be a lot 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 texture 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

The GeForce 9800 GX2 is quite a bit (more or less 773%) better at anti-aliasing than the GeForce 9400 GT 256MB, and able to handle higher resolutions without losing too much performance. (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: Bandwidth is the max amount of data (measured in megabytes per second) that can be transferred past the external memory interface within a second. The number is worked out by multiplying the interface width by its memory clock speed. If it uses DDR RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the card's 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 number of texture map elements (texels) that can be processed per second. This figure is calculated by multiplying the total texture units by the core speed of the chip. The higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card could possibly write to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.