GeForce 820M vs Radeon HD 7950 3GB

Intro

Compare all of that to the Radeon HD 7950 3GB, which has GPU core speed of 800 MHz, and 3072 MB of GDDR5 memory running at 1250 MHz through a 384-bit bus. It also is made up of 1792 Stream Processors, 112 TAUs, and 32 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 820M		15 Watts
Radeon HD 7950 3GB		200 Watts
	Difference: 185 Watts (1233%)

Memory Bandwidth

In theory, the Radeon HD 7950 3GB will be 1400% quicker than the GeForce 820M overall, due to its higher bandwidth. (explain)

Radeon HD 7950 3GB		240000 MB/sec
GeForce 820M		16000 MB/sec
	Difference: 224000 (1400%)

Texel Rate

The Radeon HD 7950 3GB should be quite a bit (about 679%) more effective at AF than the GeForce 820M. (explain)

Radeon HD 7950 3GB		89600 Mtexels/sec
GeForce 820M		11504 Mtexels/sec
	Difference: 78096 (679%)

Pixel Rate

If running with a high resolution is important to you, then the Radeon HD 7950 3GB is the winner, by a large margin. (explain)

Radeon HD 7950 3GB		25600 Mpixels/sec
GeForce 820M		2876 Mpixels/sec
	Difference: 22724 (790%)

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 largest amount of information (in units of megabytes per second) that can be moved past the external memory interface in a second. The number is worked out by multiplying the bus width by its memory clock speed. If it uses DDR memory, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. 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 texture map elements (texels) that are processed per second. This figure 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 handling 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 the graphics card can possibly write to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output 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 potential to reach the max fill rate.