Radeon HD 3870 512MB vs Radeon HD 6750 1GB

Intro

Compare all that to the Radeon HD 6750 1GB, which uses a 40 nm design. AMD has clocked the core frequency at 725 MHz. The GDDR5 memory runs at a speed of 1000 MHz on this particular model. It features 720 SPUs along with 36 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 6750 1GB		86 Watts
Radeon HD 3870 512MB		106 Watts
	Difference: 20 Watts (23%)

Memory Bandwidth

In theory, the Radeon HD 6750 1GB should perform just a bit faster than the Radeon HD 3870 512MB overall. (explain)

Radeon HD 6750 1GB		64000 MB/sec
Radeon HD 3870 512MB		57600 MB/sec
	Difference: 6400 (11%)

Texel Rate

The Radeon HD 6750 1GB should be quite a bit (about 110%) faster with regards to texture filtering than the Radeon HD 3870 512MB. (explain)

Radeon HD 6750 1GB		26100 Mtexels/sec
Radeon HD 3870 512MB		12400 Mtexels/sec
	Difference: 13700 (110%)

Pixel Rate

The Radeon HD 3870 512MB is a little bit (more or less 7%) better at AA than the Radeon HD 6750 1GB, and capable of handling higher resolutions without losing too much performance. (explain)

Radeon HD 3870 512MB		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 maximum amount of data (counted in megabytes per second) that can be transported past the external memory interface in one second. The number is worked out by multiplying the card's interface width by the speed of its memory. In the case of DDR RAM, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed in one second. This figure is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The better this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

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