GeForce 8800 GTS (G80) 640MB vs Radeon HD 6850

Intro

Compare all of that to the Radeon HD 6850, which comes with a clock frequency of 775 MHz and a GDDR5 memory speed of 1000 MHz. It also uses a 256-bit bus, and makes use of a 40 nm design. It is made up of 960 SPUs, 48 TAUs, and 32 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6850		127 Watts
GeForce 8800 GTS (G80) 640MB		143 Watts
	Difference: 16 Watts (13%)

Memory Bandwidth

In theory, the Radeon HD 6850 will be 102% quicker than the GeForce 8800 GTS (G80) 640MB overall, because of its higher bandwidth. (explain)

Radeon HD 6850		128000 MB/sec
GeForce 8800 GTS (G80) 640MB		63360 MB/sec
	Difference: 64640 (102%)

Texel Rate

The Radeon HD 6850 is a lot (more or less 51%) faster with regards to texture filtering than the GeForce 8800 GTS (G80) 640MB. (explain)

Radeon HD 6850		37200 Mtexels/sec
GeForce 8800 GTS (G80) 640MB		24624 Mtexels/sec
	Difference: 12576 (51%)

Pixel Rate

The Radeon HD 6850 is quite a bit (more or less 142%) better at FSAA than the GeForce 8800 GTS (G80) 640MB, and will be able to handle higher resolutions more effectively. (explain)

Radeon HD 6850		24800 Mpixels/sec
GeForce 8800 GTS (G80) 640MB		10260 Mpixels/sec
	Difference: 14540 (142%)

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 maximum amount of data (in units of megabytes per second) that can be moved over the external memory interface within a second. It is calculated by multiplying the interface width by its memory speed. If the card has DDR RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed in one second. This figure 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 video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.

Pixel Rate: Pixel rate is the most pixels the video card 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 amount of colour ROPs 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 fill rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.