Radeon HD 3870 X2 512MB vs Radeon HD 7970

Intro

Compare that to the Radeon HD 7970, which makes use of a 28 nm design. AMD has clocked the core speed at 925 MHz. The GDDR5 memory works at a frequency of 1375 MHz on this particular model. It features 2048 SPUs along with 128 Texture Address Units and 32 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Memory Bandwidth

Performance-wise, the Radeon HD 7970 should theoretically be much superior to the Radeon HD 3870 X2 512MB in general. (explain)

Radeon HD 7970		264000 MB/sec
Radeon HD 3870 X2 512MB		115200 MB/sec
	Difference: 148800 (129%)

Texel Rate

The Radeon HD 7970 is quite a bit (approximately 348%) more effective at AF than the Radeon HD 3870 X2 512MB. (explain)

Radeon HD 7970		118400 Mtexels/sec
Radeon HD 3870 X2 512MB		26400 Mtexels/sec
	Difference: 92000 (348%)

Pixel Rate

If running with a high screen resolution is important to you, then the Radeon HD 7970 is a better choice, but only just. (explain)

Radeon HD 7970		29600 Mpixels/sec
Radeon HD 3870 X2 512MB		26400 Mpixels/sec
	Difference: 3200 (12%)

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: Bandwidth is the maximum amount of data (measured in megabytes per second) that can be transferred over the external memory interface in a second. It is calculated by multiplying the interface width by the speed of its memory. If the card has DDR memory, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed in one second. This 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 processed in a second.

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