Radeon HD 3850 1GB vs Radeon HD 3870 1GB

Intro

Compare all that to the Radeon HD 3870 1GB, which comes with a GPU core clock speed of 775 MHz, and 1024 MB of GDDR4 memory set to run at 1125 MHz through a 256-bit bus. It also features 320(64x5) SPUs, 16 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3850 1GB		75 Watts
Radeon HD 3870 1GB		106 Watts
	Difference: 31 Watts (41%)

Memory Bandwidth

As far as performance goes, the Radeon HD 3870 1GB should in theory be quite a bit better than the Radeon HD 3850 1GB in general. (explain)

Radeon HD 3870 1GB		72000 MB/sec
Radeon HD 3850 1GB		52992 MB/sec
	Difference: 19008 (36%)

Texel Rate

The Radeon HD 3870 1GB will be a small bit (approximately 16%) faster with regards to texture filtering than the Radeon HD 3850 1GB. (explain)

Radeon HD 3870 1GB		12400 Mtexels/sec
Radeon HD 3850 1GB		10688 Mtexels/sec
	Difference: 1712 (16%)

Pixel Rate

The Radeon HD 3870 1GB is a little bit (more or less 16%) better at AA than the Radeon HD 3850 1GB, and should be capable of handling higher screen resolutions better. (explain)

Radeon HD 3870 1GB		12400 Mpixels/sec
Radeon HD 3850 1GB		10688 Mpixels/sec
	Difference: 1712 (16%)

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 largest amount of data (counted in MB per second) that can be moved over the external memory interface within a second. It is worked out by multiplying the card's bus width by its memory speed. In the case of DDR type memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the 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 processed in one second. This number is calculated by multiplying the total texture units by the core speed of the chip. The higher the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly record to the local memory in one second - measured in millions of pixels per second. Pixel rate is calculated 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 output rate is also dependant on many 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.