Radeon HD 4850 X2 512MB vs Radeon HD 7970

Intro

Compare all that to the Radeon HD 7970, which features a clock speed of 925 MHz and a GDDR5 memory frequency of 1375 MHz. It also uses a 384-bit bus, and uses 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

Both cards have the same power consumption.

Memory Bandwidth

In theory, the Radeon HD 7970 should be a lot faster than the Radeon HD 4850 X2 512MB in general. (explain)

Radeon HD 7970		264000 MB/sec
Radeon HD 4850 X2 512MB		127104 MB/sec
	Difference: 136896 (108%)

Texel Rate

The Radeon HD 7970 should be much (approximately 137%) more effective at anisotropic filtering than the Radeon HD 4850 X2 512MB. (explain)

Radeon HD 7970		118400 Mtexels/sec
Radeon HD 4850 X2 512MB		50000 Mtexels/sec
	Difference: 68400 (137%)

Pixel Rate

The Radeon HD 7970 should be much (about 48%) faster with regards to AA than the Radeon HD 4850 X2 512MB, and also capable of handling higher screen resolutions without losing too much performance. (explain)

Radeon HD 7970		29600 Mpixels/sec
Radeon HD 4850 X2 512MB		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: Memory bandwidth is the max amount of data (counted in MB per second) that can be transported over the external memory interface in a second. It is calculated by multiplying the card's interface width by the speed of its memory. In the case of DDR type RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed per second. This figure is calculated by multiplying the total number of texture units of the card 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 applied in one second.

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card could possibly write to its local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the number of colour ROPs 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, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.