Radeon HD 4650 1GB vs Radeon HD 6750 1GB

Intro

Compare all of that to the Radeon HD 6750 1GB, which comes with GPU core speed of 725 MHz, and 1024 MB of GDDR5 RAM set to run at 1000 MHz through a 128-bit bus. It also is made up of 720 SPUs, 36 TAUs, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4650 1GB		55 Watts
Radeon HD 6750 1GB		86 Watts
	Difference: 31 Watts (56%)

Memory Bandwidth

Performance-wise, the Radeon HD 6750 1GB should in theory be quite a bit better than the Radeon HD 4650 1GB overall. (explain)

Radeon HD 6750 1GB		64000 MB/sec
Radeon HD 4650 1GB		22400 MB/sec
	Difference: 41600 (186%)

Texel Rate

The Radeon HD 6750 1GB should be much (approximately 36%) better at AF than the Radeon HD 4650 1GB. (explain)

Radeon HD 6750 1GB		26100 Mtexels/sec
Radeon HD 4650 1GB		19200 Mtexels/sec
	Difference: 6900 (36%)

Pixel Rate

If using high levels of AA is important to you, then the Radeon HD 6750 1GB is a better choice, by far. (explain)

Radeon HD 6750 1GB		11600 Mpixels/sec
Radeon HD 4650 1GB		4800 Mpixels/sec
	Difference: 6800 (142%)

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 largest amount of information (in units of megabytes per second) that can be transported over the external memory interface in a second. It's worked out by multiplying the interface width by its memory speed. If it uses DDR type memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed per second. This figure is calculated by multiplying the total amount of 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 in one second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip could possibly record to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Raster Operations Pipelines by the the core 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 output rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the max fill rate.