Radeon HD 4850 X2 1GB vs Radeon HD 7970

Intro

Compare those specifications to the Radeon HD 7970, which features GPU clock speed of 925 MHz, and 3072 MB of GDDR5 RAM running at 1375 MHz through a 384-bit bus. It also is made up of 2048 SPUs, 128 TAUs, and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Both cards have the same power consumption.

Memory Bandwidth

Theoretically speaking, the Radeon HD 7970 should perform a lot faster than the Radeon HD 4850 X2 1GB in general. (explain)

Radeon HD 7970		264000 MB/sec
Radeon HD 4850 X2 1GB		127104 MB/sec
	Difference: 136896 (108%)

Texel Rate

The Radeon HD 7970 is much (approximately 137%) better at anisotropic filtering than the Radeon HD 4850 X2 1GB. (explain)

Radeon HD 7970		118400 Mtexels/sec
Radeon HD 4850 X2 1GB		50000 Mtexels/sec
	Difference: 68400 (137%)

Pixel Rate

If using a high resolution is important to you, then the Radeon HD 7970 is the winner, and very much so. (explain)

Radeon HD 7970		29600 Mpixels/sec
Radeon HD 4850 X2 1GB		20000 Mpixels/sec
	Difference: 9600 (48%)

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 (counted in MB per second) that can be transferred past the external memory interface in a second. It is worked out by multiplying the card's interface width by its memory speed. In the case of DDR RAM, 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, HDR and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be 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 higher this number, the better the 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 can possibly record to its local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Raster Operations Pipelines by the the core 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 rate also depends on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.