Radeon HD 3870 X2 1GB vs Radeon HD 7950

Intro

Compare those specifications to the Radeon HD 7950, which comes with GPU core speed of 800 MHz, and 1536 MB of GDDR5 RAM running at 1250 MHz through a 384-bit bus. It also features 1792 Stream Processors, 112 Texture Address Units, and 32 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Memory Bandwidth

Performance-wise, the Radeon HD 7950 should theoretically be a lot superior to the Radeon HD 3870 X2 1GB overall. (explain)

Radeon HD 7950		240000 MB/sec
Radeon HD 3870 X2 1GB		144128 MB/sec
	Difference: 95872 (67%)

Texel Rate

The Radeon HD 7950 is quite a bit (approximately 239%) more effective at anisotropic filtering than the Radeon HD 3870 X2 1GB. (explain)

Radeon HD 7950		89600 Mtexels/sec
Radeon HD 3870 X2 1GB		26400 Mtexels/sec
	Difference: 63200 (239%)

Pixel Rate

The Radeon HD 3870 X2 1GB should be a bit (more or less 3%) more effective at AA than the Radeon HD 7950, and also able to handle higher screen resolutions without slowing down too much. (explain)

Radeon HD 3870 X2 1GB		26400 Mpixels/sec
Radeon HD 7950		25600 Mpixels/sec
	Difference: 800 (3%)

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.

One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the largest amount of information (counted in MB per second) that can be transferred past the external memory interface in one second. It's worked out by multiplying the card's interface width by its memory speed. If it uses DDR type RAM, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the better 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 is calculated by multiplying the total number of texture units by the core speed of the chip. The better this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly write to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number of ROPs by the the card's 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 fill rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.