Radeon HD 4790 vs Radeon HD 6950 2GB

Intro

Compare all that to the Radeon HD 6950 2GB, which has clock speeds of 800 MHz on the GPU, and 1250 MHz on the 2048 MB of GDDR5 RAM. It features 1408 SPUs along with 88 Texture Address Units and 32 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Memory Bandwidth

As far as performance goes, the Radeon HD 6950 2GB should in theory be a lot better than the Radeon HD 4790 overall. (explain)

Radeon HD 6950 2GB		160000 MB/sec
Radeon HD 4790		102400 MB/sec
	Difference: 57600 (56%)

Texel Rate

The Radeon HD 6950 2GB is a lot (more or less 267%) better at AF than the Radeon HD 4790. (explain)

Radeon HD 6950 2GB		70400 Mtexels/sec
Radeon HD 4790		19200 Mtexels/sec
	Difference: 51200 (267%)

Pixel Rate

The Radeon HD 6950 2GB should be a lot (approximately 167%) more effective at full screen anti-aliasing than the Radeon HD 4790, and also will be able to handle higher resolutions without losing too much performance. (explain)

Radeon HD 6950 2GB		25600 Mpixels/sec
Radeon HD 4790		9600 Mpixels/sec
	Difference: 16000 (167%)

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 max amount of information (measured in MB per second) that can be moved over the external memory interface in one second. It's calculated by multiplying the interface width by the speed of its memory. If it uses DDR type memory, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed in one second. This number is calculated by multiplying the total texture units of the card by the core speed of the chip. The better this number, the better the video 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 video card could possibly record to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the amount of 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 rate also depends on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the max fill rate.