GeForce 8800 GTS (G80) 640MB vs Radeon HD 3870 1GB

Intro

Compare those specifications to the Radeon HD 3870 1GB, which uses a 55 nm design. AMD has set the core speed at 775 MHz. The GDDR4 memory is set to run at a frequency of 1125 MHz on this specific model. 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 8800 GTS (G80) 640MB		143 Watts
	Difference: 37 Watts (35%)

Memory Bandwidth

As far as performance goes, the Radeon HD 3870 1GB should in theory be a little bit superior to the GeForce 8800 GTS (G80) 640MB in general. (explain)

Radeon HD 3870 1GB		72000 MB/sec
GeForce 8800 GTS (G80) 640MB		63360 MB/sec
	Difference: 8640 (14%)

Texel Rate

The GeForce 8800 GTS (G80) 640MB is a lot (more or less 99%) better at texture filtering than the Radeon HD 3870 1GB. (explain)

GeForce 8800 GTS (G80) 640MB		24624 Mtexels/sec
Radeon HD 3870 1GB		12400 Mtexels/sec
	Difference: 12224 (99%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon HD 3870 1GB is a better choice, by a large margin. (explain)

Radeon HD 3870 1GB		12400 Mpixels/sec
GeForce 8800 GTS (G80) 640MB		10260 Mpixels/sec
	Difference: 2140 (21%)

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.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the max amount of information (counted in MB per second) that can be moved over the external memory interface in a second. The number is calculated by multiplying the card's interface width by the speed of its memory. In the case of DDR type memory, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. 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 texture map elements (texels) that can be applied per second. This is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The higher the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly write to its local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the number of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - also 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 of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.