GeForce 9400 GT 256MB vs GeForce 9800 GX2

Intro

Compare all of that to the GeForce 9800 GX2, which features GPU clock speed of 600 MHz, and 512 MB of GDDR3 memory running at 1000 MHz through a 256-bit bus. It also is comprised of 128 Stream Processors, 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

Performance-wise, the GeForce 9800 GX2 should in theory be a lot superior to the GeForce 9400 GT 256MB overall. (explain)

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

Texel Rate

The GeForce 9800 GX2 should be quite a bit (about 1645%) more effective at 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 a lot (about 773%) better at FSAA than the GeForce 9400 GT 256MB, and capable of handling higher screen 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 (in units of MB per second) that can be moved past the external memory interface in a second. It's calculated by multiplying the card's bus width by its memory speed. If the card has DDR type memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster 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 applied per second. This number is calculated by multiplying the total amount of texture units by the core 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 processed in a second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly record to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.