Radeon HD 4890 2GB vs Radeon HD 6950

Intro

Compare that to the Radeon HD 6950, which has GPU core speed of 800 MHz, and 1024 MB of GDDR5 memory set to run at 1250 MHz through a 256-bit bus. It also features 1408 Stream Processors, 88 Texture Address Units, and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4890 2GB		190 Watts
Radeon HD 6950		200 Watts
	Difference: 10 Watts (5%)

Memory Bandwidth

In theory, the Radeon HD 6950 will be 28% quicker than the Radeon HD 4890 2GB in general, due to its higher data rate. (explain)

Radeon HD 6950		160000 MB/sec
Radeon HD 4890 2GB		124800 MB/sec
	Difference: 35200 (28%)

Texel Rate

The Radeon HD 6950 will be a lot (more or less 76%) better at AF than the Radeon HD 4890 2GB. (explain)

Radeon HD 6950		70400 Mtexels/sec
Radeon HD 4890 2GB		40000 Mtexels/sec
	Difference: 30400 (76%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon HD 6950 is superior to the Radeon HD 4890 2GB, by a large margin. (explain)

Radeon HD 6950		25600 Mpixels/sec
Radeon HD 4890 2GB		16000 Mpixels/sec
	Difference: 9600 (60%)

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.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the max amount of data (counted in megabytes per second) that can be moved past the external memory interface within a second. It is calculated by multiplying the bus width by the speed of its memory. If the card has DDR type memory, the result should be multiplied by 2 again. If it uses 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 applied in one second. This number is calculated by multiplying the total amount of texture units by the core speed of the chip. The better the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly record to the local memory per 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 - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.