GeForce 9800 GX2 vs Radeon HD 3870 1GB

Intro

Compare all of that to the Radeon HD 3870 1GB, which uses a 55 nm design. AMD has set the core speed at 775 MHz. The GDDR4 memory runs at a frequency of 1125 MHz on this card. It features 320(64x5) SPUs as well as 16 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3870 1GB		106 Watts
GeForce 9800 GX2		197 Watts
	Difference: 91 Watts (86%)

Memory Bandwidth

Theoretically speaking, the GeForce 9800 GX2 should be 78% faster than the Radeon HD 3870 1GB in general, due to its greater data rate. (explain)

GeForce 9800 GX2		128000 MB/sec
Radeon HD 3870 1GB		72000 MB/sec
	Difference: 56000 (78%)

Texel Rate

The GeForce 9800 GX2 is much (more or less 519%) more effective at anisotropic filtering than the Radeon HD 3870 1GB. (explain)

GeForce 9800 GX2		76800 Mtexels/sec
Radeon HD 3870 1GB		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 a better choice, by a large margin. (explain)

GeForce 9800 GX2		19200 Mpixels/sec
Radeon HD 3870 1GB		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: Bandwidth is the largest amount of data (counted in megabytes per second) that can be moved across the external memory interface in one second. It's calculated by multiplying the bus width by the speed of its memory. If the card has DDR RAM, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the card's memory bandwidth, the better 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 amount of texture map elements (texels) that are processed per second. This is worked out by multiplying the total amount of texture units by the core speed of the chip. The higher the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.

Pixel Rate: Pixel rate is the most pixels the graphics 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 speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.