Radeon HD 4550 256MB vs Radeon HD 4650 512MB

Intro

Compare all that to the Radeon HD 4650 512MB, which uses a 55 nm design. AMD has set the core speed at 600 MHz. The DDR2 memory runs at a speed of 500 MHz on this particular card. It features 320(64x5) SPUs as well as 32 TAUs and 8 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4550 256MB		25 Watts
Radeon HD 4650 512MB		55 Watts
	Difference: 30 Watts (120%)

Memory Bandwidth

In theory, the Radeon HD 4650 512MB should perform a lot faster than the Radeon HD 4550 256MB overall. (explain)

Radeon HD 4650 512MB		16000 MB/sec
Radeon HD 4550 256MB		12800 MB/sec
	Difference: 3200 (25%)

Texel Rate

The Radeon HD 4650 512MB will be quite a bit (approximately 300%) better at anisotropic filtering than the Radeon HD 4550 256MB. (explain)

Radeon HD 4650 512MB		19200 Mtexels/sec
Radeon HD 4550 256MB		4800 Mtexels/sec
	Difference: 14400 (300%)

Pixel Rate

If running with high levels of AA is important to you, then the Radeon HD 4650 512MB is the winner, by far. (explain)

Radeon HD 4650 512MB		4800 Mpixels/sec
Radeon HD 4550 256MB		2400 Mpixels/sec
	Difference: 2400 (100%)

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 maximum amount of data (counted in MB per second) that can be transported across the external memory interface within a second. It is calculated by multiplying the bus width by its memory speed. If it uses DDR memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed in one second. This figure is calculated by multiplying the total number of texture units by the core speed of the chip. The better this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly write to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.