Radeon HD 3870 1GB vs Radeon HD 6950 2GB

Intro

Compare those specifications to the Radeon HD 6950 2GB, which makes use of a 40 nm design. AMD has set the core frequency at 800 MHz. The GDDR5 RAM works at a speed of 1250 MHz on this card. It features 1408 SPUs along with 88 Texture Address Units and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3870 1GB		106 Watts
Radeon HD 6950 2GB		200 Watts
	Difference: 94 Watts (89%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 6950 2GB is 122% faster than the Radeon HD 3870 1GB overall, because of its greater data rate. (explain)

Radeon HD 6950 2GB		160000 MB/sec
Radeon HD 3870 1GB		72000 MB/sec
	Difference: 88000 (122%)

Texel Rate

The Radeon HD 6950 2GB should be much (more or less 468%) faster with regards to texture filtering than the Radeon HD 3870 1GB. (explain)

Radeon HD 6950 2GB		70400 Mtexels/sec
Radeon HD 3870 1GB		12400 Mtexels/sec
	Difference: 58000 (468%)

Pixel Rate

The Radeon HD 6950 2GB should be quite a bit (more or less 106%) more effective at full screen anti-aliasing than the Radeon HD 3870 1GB, and also should be able to handle higher resolutions more effectively. (explain)

Radeon HD 6950 2GB		25600 Mpixels/sec
Radeon HD 3870 1GB		12400 Mpixels/sec
	Difference: 13200 (106%)

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 (counted in MB per second) that can be transported over the external memory interface in one second. It's calculated by multiplying the card's interface width by its memory speed. In the case of DDR type memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR 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 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 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 could possibly record to its local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the amount of Render Output Units by the the core 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 quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.