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

Intro

Compare those specs to the Radeon HD 3870 1GB, which uses a 55 nm design. AMD has clocked the core speed at 775 MHz. The GDDR4 RAM is set to run at a frequency of 1125 MHz on this model. It features 320(64x5) SPUs along with 16 Texture Address Units and 16 ROPs.

Display Graphs

Hide Graphs

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 better than 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 will be much (approximately 99%) more effective at AF 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

The Radeon HD 3870 1GB is quite a bit (about 21%) faster with regards to full screen anti-aliasing than the GeForce 8800 GTS (G80) 640MB, and also able to handle higher resolutions without losing too much performance. (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 data (counted in megabytes per second) that can be transferred over the external memory interface in a second. The number is calculated by multiplying the bus width by the speed of its memory. If it uses DDR type memory, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied per second. This is worked out by multiplying the total number of texture units of the card by the core clock 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 most pixels the video card could possibly record to its local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate also depends on many other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the max fill rate.