Radeon HD 4550 512MB vs Radeon HD 5550

Intro

Compare all of that to the Radeon HD 5550, which features a clock speed of 550 MHz and a DDR2 memory frequency of 400 MHz. It also features a 128-bit bus, and uses a 40 nm design. It is made up of 320(64x5) SPUs, 16 Texture Address Units, and 8 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

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

Texel Rate

The Radeon HD 5550 is much (about 83%) more effective at texture 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 the winner, and very much so. (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: Bandwidth is the max amount of data (counted in megabytes per second) that can be transferred over the external memory interface in a second. It's worked out by multiplying the bus width by its memory speed. If the card has DDR type memory, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the card's memory bandwidth, the better 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 number of texture map elements (texels) that are applied in one second. This is calculated by multiplying the total texture units of the card by the core speed of the chip. The higher this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

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