Radeon HD 3870 1GB vs Radeon HD 6850

Intro

Compare those specifications to the Radeon HD 6850, which features clock speeds of 775 MHz on the GPU, and 1000 MHz on the 1024 MB of GDDR5 memory. It features 960 SPUs along with 48 Texture Address Units and 32 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3870 1GB		106 Watts
Radeon HD 6850		127 Watts
	Difference: 21 Watts (20%)

Memory Bandwidth

Performance-wise, the Radeon HD 6850 should theoretically be much superior to the Radeon HD 3870 1GB in general. (explain)

Radeon HD 6850		128000 MB/sec
Radeon HD 3870 1GB		72000 MB/sec
	Difference: 56000 (78%)

Texel Rate

The Radeon HD 6850 is much (about 200%) faster with regards to AF than the Radeon HD 3870 1GB. (explain)

Radeon HD 6850		37200 Mtexels/sec
Radeon HD 3870 1GB		12400 Mtexels/sec
	Difference: 24800 (200%)

Pixel Rate

The Radeon HD 6850 is a lot (approximately 100%) faster with regards to FSAA than the Radeon HD 3870 1GB, and should be able to handle higher resolutions without losing too much performance. (explain)

Radeon HD 6850		24800 Mpixels/sec
Radeon HD 3870 1GB		12400 Mpixels/sec
	Difference: 12400 (100%)

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 data (counted in megabytes per second) that can be transferred across the external memory interface within a second. It's calculated by multiplying the interface width by its memory speed. If it uses DDR type RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher 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 texture map elements (texels) that are applied in one second. This number is calculated by multiplying the total amount of texture units by the core clock speed of the chip. The better this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

Pixel Rate: Pixel rate is the most pixels the video card could possibly record to the local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.