Radeon HD 3850 X2 vs Radeon HD 7970

Intro

Compare all that to the Radeon HD 7970, which features a core clock frequency of 925 MHz and a GDDR5 memory speed of 1375 MHz. It also uses a 384-bit bus, and makes use of a 28 nm design. It is made up of 2048 SPUs, 128 Texture Address Units, and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Memory Bandwidth

Theoretically speaking, the Radeon HD 7970 will be 149% quicker than the Radeon HD 3850 X2 in general, because of its higher bandwidth. (explain)

Radeon HD 7970		264000 MB/sec
Radeon HD 3850 X2		105984 MB/sec
	Difference: 158016 (149%)

Texel Rate

The Radeon HD 7970 is a lot (approximately 454%) more effective at AF than the Radeon HD 3850 X2. (explain)

Radeon HD 7970		118400 Mtexels/sec
Radeon HD 3850 X2		21376 Mtexels/sec
	Difference: 97024 (454%)

Pixel Rate

The Radeon HD 7970 should be much (more or less 38%) faster with regards to full screen anti-aliasing than the Radeon HD 3850 X2, and capable of handling higher resolutions more effectively. (explain)

Radeon HD 7970		29600 Mpixels/sec
Radeon HD 3850 X2		21376 Mpixels/sec
	Difference: 8224 (38%)

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 maximum amount of information (measured in MB per second) that can be moved across the external memory interface in one second. It's calculated by multiplying the card's bus width by its memory clock speed. If it uses DDR type memory, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed in one second. This is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The better this number, 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 amount of pixels the video card could possibly record to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the number 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 rate is also dependant on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.