Radeon HD 3850 256MB vs Radeon HD 6850

Intro

Compare those specs to the Radeon HD 6850, which comes with GPU clock speed of 775 MHz, and 1024 MB of GDDR5 memory set to run at 1000 MHz through a 256-bit bus. It also is made up of 960 Stream Processors, 48 Texture Address Units, and 32 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3850 256MB		75 Watts
Radeon HD 6850		127 Watts
	Difference: 52 Watts (69%)

Memory Bandwidth

The Radeon HD 6850 should in theory be a lot faster than the Radeon HD 3850 256MB in general. (explain)

Radeon HD 6850		128000 MB/sec
Radeon HD 3850 256MB		52992 MB/sec
	Difference: 75008 (142%)

Texel Rate

The Radeon HD 6850 is quite a bit (more or less 248%) faster with regards to AF than the Radeon HD 3850 256MB. (explain)

Radeon HD 6850		37200 Mtexels/sec
Radeon HD 3850 256MB		10688 Mtexels/sec
	Difference: 26512 (248%)

Pixel Rate

If using a high screen resolution is important to you, then the Radeon HD 6850 is superior to the Radeon HD 3850 256MB, and very much so. (explain)

Radeon HD 6850		24800 Mpixels/sec
Radeon HD 3850 256MB		10688 Mpixels/sec
	Difference: 14112 (132%)

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 largest amount of information (in units of MB per second) that can be moved past the external memory interface in a second. The number is worked out by multiplying the card's bus width by its memory speed. If it uses DDR RAM, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the better 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 number of texture map elements (texels) that can be processed 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 the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Raster Operations Pipelines by the the card's clock speed. 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 is also dependant on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.