Radeon HD 3870 512MB vs Radeon HD 6870

Intro

Compare those specs to the Radeon HD 6870, which comes with clock speeds of 900 MHz on the GPU, and 1050 MHz on the 1024 MB of GDDR5 memory. It features 1120 SPUs along with 56 TAUs and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3870 512MB		106 Watts
Radeon HD 6870		151 Watts
	Difference: 45 Watts (42%)

Memory Bandwidth

In theory, the Radeon HD 6870 should be 133% quicker than the Radeon HD 3870 512MB overall, because of its higher data rate. (explain)

Radeon HD 6870		134400 MB/sec
Radeon HD 3870 512MB		57600 MB/sec
	Difference: 76800 (133%)

Texel Rate

The Radeon HD 6870 is a lot (approximately 306%) faster with regards to AF than the Radeon HD 3870 512MB. (explain)

Radeon HD 6870		50400 Mtexels/sec
Radeon HD 3870 512MB		12400 Mtexels/sec
	Difference: 38000 (306%)

Pixel Rate

If running with high levels of AA is important to you, then the Radeon HD 6870 is the winner, and very much so. (explain)

Radeon HD 6870		28800 Mpixels/sec
Radeon HD 3870 512MB		12400 Mpixels/sec
	Difference: 16400 (132%)

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 largest amount of data (measured in MB per second) that can be transported past the external memory interface in a second. The number is worked out by multiplying the card's bus width by its memory speed. In the case of DDR memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster 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 in one second. This figure is calculated by multiplying the total amount of texture units of the card by the core speed of the chip. The better the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly write to its local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the amount of colour ROPs by the clock 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 output rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.