Radeon HD 4550 256MB vs Radeon HD 6950

Intro

Compare that to the Radeon HD 6950, which has clock speeds of 800 MHz on the GPU, and 1250 MHz on the 1024 MB of GDDR5 memory. 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 4550 256MB		25 Watts
Radeon HD 6950		200 Watts
	Difference: 175 Watts (700%)

Memory Bandwidth

As far as performance goes, the Radeon HD 6950 should theoretically be much superior to the Radeon HD 4550 256MB in general. (explain)

Radeon HD 6950		160000 MB/sec
Radeon HD 4550 256MB		12800 MB/sec
	Difference: 147200 (1150%)

Texel Rate

The Radeon HD 6950 should be much (about 1367%) more effective at anisotropic filtering than the Radeon HD 4550 256MB. (explain)

Radeon HD 6950		70400 Mtexels/sec
Radeon HD 4550 256MB		4800 Mtexels/sec
	Difference: 65600 (1367%)

Pixel Rate

The Radeon HD 6950 will be much (approximately 967%) more effective at AA than the Radeon HD 4550 256MB, and will be capable of handling higher screen resolutions without losing too much performance. (explain)

Radeon HD 6950		25600 Mpixels/sec
Radeon HD 4550 256MB		2400 Mpixels/sec
	Difference: 23200 (967%)

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 (in units of MB per second) that can be transported past the external memory interface within a second. It is calculated by multiplying the interface width by its memory clock speed. If it uses DDR RAM, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly record to the local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.