Radeon HD 6790 vs Radeon HD 6950 2GB

Intro

Compare all of that to the Radeon HD 6950 2GB, which features a GPU core clock speed of 800 MHz, and 2048 MB of GDDR5 RAM set to run at 1250 MHz through a 256-bit bus. It also features 1408 Stream Processors, 88 Texture Address Units, and 32 Raster Operation Units.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6790		150 Watts
Radeon HD 6950 2GB		200 Watts
	Difference: 50 Watts (33%)

Memory Bandwidth

As far as performance goes, the Radeon HD 6950 2GB should theoretically be just a bit superior to the Radeon HD 6790 in general. (explain)

Radeon HD 6950 2GB		160000 MB/sec
Radeon HD 6790		134400 MB/sec
	Difference: 25600 (19%)

Texel Rate

The Radeon HD 6950 2GB is much (approximately 110%) better at anisotropic filtering than the Radeon HD 6790. (explain)

Radeon HD 6950 2GB		70400 Mtexels/sec
Radeon HD 6790		33600 Mtexels/sec
	Difference: 36800 (110%)

Pixel Rate

If running with lots of anti-aliasing is important to you, then the Radeon HD 6950 2GB is a better choice, by a large margin. (explain)

Radeon HD 6950 2GB		25600 Mpixels/sec
Radeon HD 6790		13440 Mpixels/sec
	Difference: 12160 (90%)

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 (measured in megabytes per second) that can be moved across the external memory interface within a second. It's worked out by multiplying the bus width by its memory speed. If it uses DDR RAM, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied per second. This number is worked out by multiplying the total amount of texture units of the card by the core clock 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 processed per second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card could possibly write to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.