Radeon HD 4550 256MB vs Radeon HD 6450 (OEM) 1GB

Intro

Compare those specifications to the Radeon HD 6450 (OEM) 1GB, which has a clock frequency of 750 MHz and a GDDR5 memory speed of 900 MHz. It also uses a 64-bit bus, and uses a 40 nm design. It is made up of 160 SPUs, 8 TAUs, and 4 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 6450 (OEM) 1GB		31 Watts
	Difference: 6 Watts (24%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 6450 (OEM) 1GB should perform a lot faster than the Radeon HD 4550 256MB overall. (explain)

Radeon HD 6450 (OEM) 1GB		28800 MB/sec
Radeon HD 4550 256MB		12800 MB/sec
	Difference: 16000 (125%)

Texel Rate

The Radeon HD 6450 (OEM) 1GB should be quite a bit (more or less 25%) faster with regards to AF than the Radeon HD 4550 256MB. (explain)

Radeon HD 6450 (OEM) 1GB		6000 Mtexels/sec
Radeon HD 4550 256MB		4800 Mtexels/sec
	Difference: 1200 (25%)

Pixel Rate

If running with a high screen resolution is important to you, then the Radeon HD 6450 (OEM) 1GB is a better choice, and very much so. (explain)

Radeon HD 6450 (OEM) 1GB		3000 Mpixels/sec
Radeon HD 4550 256MB		2400 Mpixels/sec
	Difference: 600 (25%)

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 data (counted in MB per second) that can be moved across the external memory interface within a second. It is 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 ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied per second. This number is worked out by multiplying the total texture units by the core speed of the chip. The better this number, the better the graphics 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 graphics card can possibly record to its local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant 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 max fill rate.