Radeon HD 3850 1GB vs Radeon HD 3870 1GB

Intro

Compare those specifications to the Radeon HD 3870 1GB, which makes use of a 55 nm design. AMD has set the core speed at 775 MHz. The GDDR4 RAM is set to run at a speed of 1125 MHz on this particular model. It features 320(64x5) SPUs as well as 16 Texture Address Units and 16 Rasterization Operator 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

In theory, the Radeon HD 3870 1GB should be 36% quicker than the Radeon HD 3850 1GB in general, due to its higher bandwidth. (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 should be a small bit (approximately 16%) better at AF 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

If using lots of anti-aliasing is important to you, then the Radeon HD 3870 1GB is the winner, not by a very large margin though. (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 information (measured in MB per second) that can be transferred across the external memory interface in one second. It is worked out by multiplying the card's bus width by the speed of its memory. If the card has DDR memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster the card will be in general. It especially helps with AA, 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 figure is worked out by multiplying the total number 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 write to the local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.