Radeon HD 3850 256MB vs Radeon HD 6750 1GB

Intro

Compare those specs to the Radeon HD 6750 1GB, which features a core clock speed of 725 MHz and a GDDR5 memory speed of 1000 MHz. It also features a 128-bit bus, and makes use of a 40 nm design. It features 720 SPUs, 36 Texture Address Units, and 16 Raster Operation Units.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3850 256MB		75 Watts
Radeon HD 6750 1GB		86 Watts
	Difference: 11 Watts (15%)

Memory Bandwidth

In theory, the Radeon HD 6750 1GB is 21% quicker than the Radeon HD 3850 256MB overall, because of its greater bandwidth. (explain)

Radeon HD 6750 1GB		64000 MB/sec
Radeon HD 3850 256MB		52992 MB/sec
	Difference: 11008 (21%)

Texel Rate

The Radeon HD 6750 1GB should be much (about 144%) more effective at anisotropic filtering than the Radeon HD 3850 256MB. (explain)

Radeon HD 6750 1GB		26100 Mtexels/sec
Radeon HD 3850 256MB		10688 Mtexels/sec
	Difference: 15412 (144%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon HD 6750 1GB is the winner, not by a very large margin though. (explain)

Radeon HD 6750 1GB		11600 Mpixels/sec
Radeon HD 3850 256MB		10688 Mpixels/sec
	Difference: 912 (9%)

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 megabytes per second) that can be transferred over the external memory interface in one second. It's calculated by multiplying the card's bus width by its memory clock speed. In the case of DDR RAM, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics 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 number of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.