Radeon HD 3690/3830 vs Radeon HD 7870

Intro

Compare that to the Radeon HD 7870, which comes with a GPU core clock speed of 1000 MHz, and 2048 MB of GDDR5 RAM set to run at 1200 MHz through a 256-bit bus. It also is made up of 1280 Stream Processors, 80 TAUs, and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3690/3830		75 Watts
Radeon HD 7870		175 Watts
	Difference: 100 Watts (133%)

Memory Bandwidth

As far as performance goes, the Radeon HD 7870 should theoretically be quite a bit superior to the Radeon HD 3690/3830 overall. (explain)

Radeon HD 7870		153600 MB/sec
Radeon HD 3690/3830		26496 MB/sec
	Difference: 127104 (480%)

Texel Rate

The Radeon HD 7870 will be a lot (approximately 649%) more effective at texture filtering than the Radeon HD 3690/3830. (explain)

Radeon HD 7870		80000 Mtexels/sec
Radeon HD 3690/3830		10688 Mtexels/sec
	Difference: 69312 (649%)

Pixel Rate

If using a high screen resolution is important to you, then the Radeon HD 7870 is a better choice, by far. (explain)

Radeon HD 7870		32000 Mpixels/sec
Radeon HD 3690/3830		10688 Mpixels/sec
	Difference: 21312 (199%)

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 information (counted in MB per second) that can be transported past the external memory interface in a second. It is calculated by multiplying the interface width by its memory clock speed. If it uses DDR type RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied in one second. This figure is worked out by multiplying the total number 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 applied in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly record to the local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on many 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.