GeForce 9800 GX2 vs Radeon HD 3870 512MB

Intro

Compare that to the Radeon HD 3870 512MB, which has GPU clock speed of 775 MHz, and 512 MB of GDDR3 RAM running at 900 MHz through a 256-bit bus. It also is made up of 320(64x5) SPUs, 16 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3870 512MB		106 Watts
GeForce 9800 GX2		197 Watts
	Difference: 91 Watts (86%)

Memory Bandwidth

As far as performance goes, the GeForce 9800 GX2 should theoretically be quite a bit superior to the Radeon HD 3870 512MB overall. (explain)

GeForce 9800 GX2		128000 MB/sec
Radeon HD 3870 512MB		57600 MB/sec
	Difference: 70400 (122%)

Texel Rate

The GeForce 9800 GX2 is a lot (approximately 519%) faster with regards to anisotropic filtering than the Radeon HD 3870 512MB. (explain)

GeForce 9800 GX2		76800 Mtexels/sec
Radeon HD 3870 512MB		12400 Mtexels/sec
	Difference: 64400 (519%)

Pixel Rate

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

GeForce 9800 GX2		19200 Mpixels/sec
Radeon HD 3870 512MB		12400 Mpixels/sec
	Difference: 6800 (55%)

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 (in units of megabytes per second) that can be moved past the external memory interface within a second. The number is calculated by multiplying the card's interface width by its memory clock speed. In the case of DDR memory, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the card's 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 number of texture map elements (texels) that are applied in one second. This is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The better this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.

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