Radeon HD 4850 2GB vs Radeon HD 6950 2GB

Intro

Compare that to the Radeon HD 6950 2GB, which comes with core speeds of 800 MHz on the GPU, and 1250 MHz on the 2048 MB of GDDR5 RAM. It features 1408 SPUs as well as 88 Texture Address Units and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4850 2GB		110 Watts
Radeon HD 6950 2GB		200 Watts
	Difference: 90 Watts (82%)

Memory Bandwidth

In theory, the Radeon HD 6950 2GB should be 152% faster than the Radeon HD 4850 2GB in general, due to its higher data rate. (explain)

Radeon HD 6950 2GB		160000 MB/sec
Radeon HD 4850 2GB		63552 MB/sec
	Difference: 96448 (152%)

Texel Rate

The Radeon HD 6950 2GB will be much (more or less 182%) faster with regards to AF than the Radeon HD 4850 2GB. (explain)

Radeon HD 6950 2GB		70400 Mtexels/sec
Radeon HD 4850 2GB		25000 Mtexels/sec
	Difference: 45400 (182%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon HD 6950 2GB is a better choice, and very much so. (explain)

Radeon HD 6950 2GB		25600 Mpixels/sec
Radeon HD 4850 2GB		10000 Mpixels/sec
	Difference: 15600 (156%)

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: Memory bandwidth is the maximum amount of information (counted in MB per second) that can be moved over the external memory interface in a second. The number is worked out by multiplying the card's bus width by its memory speed. If the card has DDR RAM, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied in one second. This figure is calculated by multiplying the total texture units of the card by the core speed of the chip. The higher the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly write to its local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.