Radeon HD 4550 512MB 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 RAM set to run 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 512MB		25 Watts
Radeon HD 6770		108 Watts
	Difference: 83 Watts (332%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 6770 is 425% quicker than the Radeon HD 4550 512MB in general, because of its higher data rate. (explain)

Radeon HD 6770		67200 MB/sec
Radeon HD 4550 512MB		12800 MB/sec
	Difference: 54400 (425%)

Texel Rate

The Radeon HD 6770 will be quite a bit (approximately 650%) more effective at texture filtering than the Radeon HD 4550 512MB. (explain)

Radeon HD 6770		36000 Mtexels/sec
Radeon HD 4550 512MB		4800 Mtexels/sec
	Difference: 31200 (650%)

Pixel Rate

The Radeon HD 6770 is a lot (approximately 500%) better at AA than the Radeon HD 4550 512MB, and also should be capable of handling higher resolutions without losing too much performance. (explain)

Radeon HD 6770		14400 Mpixels/sec
Radeon HD 4550 512MB		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 max amount of information (measured in megabytes per second) that can be moved past the external memory interface in a second. It is calculated by multiplying the interface width by its memory clock speed. In the case of DDR memory, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, HDR 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 number of texture units by the core speed of the chip. The better the texel rate, the better the video card will be at handling 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 the graphics card can possibly record to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of colour 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 rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.