Radeon HD 4550 512MB vs Radeon HD 5550

Intro

Compare all that to the Radeon HD 5550, which features a GPU core clock speed of 550 MHz, and 512 MB of DDR2 memory set to run at 400 MHz through a 128-bit bus. It also is made up of 320(64x5) SPUs, 16 Texture Address Units, and 8 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Memory Bandwidth

Both cards have exactly the same bandwidth, so theoretically they should perform the same. (explain)

Texel Rate

The Radeon HD 5550 will be quite a bit (more or less 83%) better at anisotropic filtering than the Radeon HD 4550 512MB. (explain)

Radeon HD 5550		8800 Mtexels/sec
Radeon HD 4550 512MB		4800 Mtexels/sec
	Difference: 4000 (83%)

Pixel Rate

If running with lots of anti-aliasing is important to you, then the Radeon HD 5550 is a better choice, by a large margin. (explain)

Radeon HD 5550		4400 Mpixels/sec
Radeon HD 4550 512MB		2400 Mpixels/sec
	Difference: 2000 (83%)

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 (counted in MB per second) that can be transferred across the external memory interface in one second. It's calculated by multiplying the bus width by its memory speed. If it uses DDR type RAM, it must be multiplied by 2 once again. If 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 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 per second.

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