Radeon HD 4550 256MB vs Radeon HD 6950

Intro

Compare that to the Radeon HD 6950, which features core 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 in theory be much superior to the Radeon HD 4550 256MB overall. (explain)

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

Texel Rate

The Radeon HD 6950 is quite a bit (approximately 1367%) faster with regards to 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 a lot (about 967%) faster with regards to full screen anti-aliasing than the Radeon HD 4550 256MB, and also should 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 (measured in megabytes per second) that can be transported past the external memory interface within a second. It is calculated by multiplying the card's bus width by its memory speed. If the card has DDR RAM, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the better 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 amount of texture map elements (texels) that are processed in one second. This is calculated by multiplying the total texture units by the core speed of the chip. The higher this number, the better the graphics 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 amount of pixels that the graphics chip could possibly record to the 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 the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant 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.