Radeon HD 4850 X2 512MB vs Radeon HD 6950

Intro

Compare those specs to the Radeon HD 6950, which uses a 40 nm design. AMD has clocked the core speed at 800 MHz. The GDDR5 RAM is set to run at a frequency of 1250 MHz on this specific model. It features 1408 SPUs as well as 88 Texture Address Units and 32 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6950		200 Watts
Radeon HD 4850 X2 512MB		250 Watts
	Difference: 50 Watts (25%)

Memory Bandwidth

The Radeon HD 6950 should in theory be a lot faster than the Radeon HD 4850 X2 512MB overall. (explain)

Radeon HD 6950		160000 MB/sec
Radeon HD 4850 X2 512MB		127104 MB/sec
	Difference: 32896 (26%)

Texel Rate

The Radeon HD 6950 should be quite a bit (approximately 41%) more effective at AF than the Radeon HD 4850 X2 512MB. (explain)

Radeon HD 6950		70400 Mtexels/sec
Radeon HD 4850 X2 512MB		50000 Mtexels/sec
	Difference: 20400 (41%)

Pixel Rate

If using high levels of AA is important to you, then the Radeon HD 6950 is superior to the Radeon HD 4850 X2 512MB, by a large margin. (explain)

Radeon HD 6950		25600 Mpixels/sec
Radeon HD 4850 X2 512MB		20000 Mpixels/sec
	Difference: 5600 (28%)

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 max amount of data (counted in MB per second) that can be transferred past the external memory interface in one second. It's calculated by multiplying the bus width by its memory clock speed. If the card has DDR RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen 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 number of texture units of the card by the core clock speed of the chip. The higher this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Raster Operations Pipelines by the the core 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 rate also depends on many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.