Radeon HD 3870 512MB vs Radeon HD 4550 512MB

Intro

Compare those specifications to the Radeon HD 4550 512MB, which uses a 55 nm design. AMD has clocked the core speed at 600 MHz. The GDDR3 RAM runs at a frequency of 800 MHz on this card. It features 80(16x5) SPUs as well as 8 Texture Address Units and 4 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4550 512MB		25 Watts
Radeon HD 3870 512MB		106 Watts
	Difference: 81 Watts (324%)

Memory Bandwidth

As far as performance goes, the Radeon HD 3870 512MB should theoretically be much superior to the Radeon HD 4550 512MB in general. (explain)

Radeon HD 3870 512MB		57600 MB/sec
Radeon HD 4550 512MB		12800 MB/sec
	Difference: 44800 (350%)

Texel Rate

The Radeon HD 3870 512MB is quite a bit (approximately 158%) better at anisotropic filtering than the Radeon HD 4550 512MB. (explain)

Radeon HD 3870 512MB		12400 Mtexels/sec
Radeon HD 4550 512MB		4800 Mtexels/sec
	Difference: 7600 (158%)

Pixel Rate

The Radeon HD 3870 512MB is much (approximately 417%) better at full screen anti-aliasing than the Radeon HD 4550 512MB, and also able to handle higher screen resolutions without slowing down too much. (explain)

Radeon HD 3870 512MB		12400 Mpixels/sec
Radeon HD 4550 512MB		2400 Mpixels/sec
	Difference: 10000 (417%)

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 MB per second) that can be moved over the external memory interface within a second. It's calculated by multiplying the interface width by its memory speed. In the case of DDR memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, 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 applied in one second. This figure is worked out by multiplying the total number of texture units of the card by the core speed of the chip. The higher the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the most pixels the graphics card can possibly write to its local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of 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 fill rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.