Radeon HD 4550 256MB vs Radeon HD 6770

Intro

Compare all of that to the Radeon HD 6770, which has GPU core speed of 900 MHz, and 512 MB of GDDR5 memory running at 1050 MHz through a 128-bit bus. It also is comprised of 800 SPUs, 40 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4550 256MB		25 Watts
Radeon HD 6770		108 Watts
	Difference: 83 Watts (332%)

Memory Bandwidth

In theory, the Radeon HD 6770 is 425% quicker than the Radeon HD 4550 256MB overall, due to its higher bandwidth. (explain)

Radeon HD 6770		67200 MB/sec
Radeon HD 4550 256MB		12800 MB/sec
	Difference: 54400 (425%)

Texel Rate

The Radeon HD 6770 should be quite a bit (about 650%) more effective at anisotropic filtering than the Radeon HD 4550 256MB. (explain)

Radeon HD 6770		36000 Mtexels/sec
Radeon HD 4550 256MB		4800 Mtexels/sec
	Difference: 31200 (650%)

Pixel Rate

If using a high screen resolution is important to you, then the Radeon HD 6770 is superior to the Radeon HD 4550 256MB, by a large margin. (explain)

Radeon HD 6770		14400 Mpixels/sec
Radeon HD 4550 256MB		2400 Mpixels/sec
	Difference: 12000 (500%)

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 across the external memory interface in one second. It's worked out by multiplying the interface width by its memory clock speed. If it uses DDR memory, the result should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed in one second. This number is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The better the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.

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