Radeon HD 3870 1GB vs Radeon HD 6750 1GB

Intro

Compare those specifications to the Radeon HD 6750 1GB, which comes with GPU clock speed of 725 MHz, and 1024 MB of GDDR5 memory running at 1000 MHz through a 128-bit bus. It also features 720 SPUs, 36 TAUs, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6750 1GB		86 Watts
Radeon HD 3870 1GB		106 Watts
	Difference: 20 Watts (23%)

Memory Bandwidth

In theory, the Radeon HD 3870 1GB will be 13% quicker than the Radeon HD 6750 1GB in general, because of its greater data rate. (explain)

Radeon HD 3870 1GB		72000 MB/sec
Radeon HD 6750 1GB		64000 MB/sec
	Difference: 8000 (13%)

Texel Rate

The Radeon HD 6750 1GB should be quite a bit (approximately 110%) faster with regards to anisotropic filtering than the Radeon HD 3870 1GB. (explain)

Radeon HD 6750 1GB		26100 Mtexels/sec
Radeon HD 3870 1GB		12400 Mtexels/sec
	Difference: 13700 (110%)

Pixel Rate

If running with lots of anti-aliasing is important to you, then the Radeon HD 3870 1GB is superior to the Radeon HD 6750 1GB, though only just barely. (explain)

Radeon HD 3870 1GB		12400 Mpixels/sec
Radeon HD 6750 1GB		11600 Mpixels/sec
	Difference: 800 (7%)

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

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly record to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the max fill rate.