GeForce 8800 GTS (G80) 320MB vs Radeon HD 3870 512MB

Intro

Compare those specs to the Radeon HD 3870 512MB, which comes with a clock frequency of 775 MHz and a GDDR3 memory frequency of 900 MHz. It also makes use of a 256-bit memory bus, and uses a 55 nm design. It is comprised of 320(64x5) SPUs, 16 TAUs, 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 8800 GTS (G80) 320MB		143 Watts
	Difference: 37 Watts (35%)

Memory Bandwidth

The GeForce 8800 GTS (G80) 320MB should in theory be just a bit faster than the Radeon HD 3870 512MB overall. (explain)

GeForce 8800 GTS (G80) 320MB		63360 MB/sec
Radeon HD 3870 512MB		57600 MB/sec
	Difference: 5760 (10%)

Texel Rate

The GeForce 8800 GTS (G80) 320MB will be much (more or less 99%) faster with regards to anisotropic filtering than the Radeon HD 3870 512MB. (explain)

GeForce 8800 GTS (G80) 320MB		24624 Mtexels/sec
Radeon HD 3870 512MB		12400 Mtexels/sec
	Difference: 12224 (99%)

Pixel Rate

The Radeon HD 3870 512MB will be a lot (approximately 21%) more effective at full screen anti-aliasing than the GeForce 8800 GTS (G80) 320MB, and also should be able to handle higher screen resolutions without losing too much performance. (explain)

Radeon HD 3870 512MB		12400 Mpixels/sec
GeForce 8800 GTS (G80) 320MB		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: Bandwidth is the max amount of information (in units of MB per second) that can be transported across the external memory interface within a second. It is calculated by multiplying the card's bus width by its memory speed. If it uses DDR type memory, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher 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 number of texture map elements (texels) that can be applied in one second. This number is calculated by multiplying the total 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 handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.

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