Radeon HD 4670 512MB vs Radeon HD 6850

Intro

Compare that to the Radeon HD 6850, which comes with a core clock speed of 775 MHz and a GDDR5 memory frequency of 1000 MHz. It also features a 256-bit bus, and makes use of a 40 nm design. It is comprised of 960 SPUs, 48 Texture Address Units, and 32 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4670 512MB		70 Watts
Radeon HD 6850		127 Watts
	Difference: 57 Watts (81%)

Memory Bandwidth

As far as performance goes, the Radeon HD 6850 should in theory be quite a bit superior to the Radeon HD 4670 512MB in general. (explain)

Radeon HD 6850		128000 MB/sec
Radeon HD 4670 512MB		32000 MB/sec
	Difference: 96000 (300%)

Texel Rate

The Radeon HD 6850 is quite a bit (more or less 55%) faster with regards to AF than the Radeon HD 4670 512MB. (explain)

Radeon HD 6850		37200 Mtexels/sec
Radeon HD 4670 512MB		24000 Mtexels/sec
	Difference: 13200 (55%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon HD 6850 is superior to the Radeon HD 4670 512MB, and very much so. (explain)

Radeon HD 6850		24800 Mpixels/sec
Radeon HD 4670 512MB		6000 Mpixels/sec
	Difference: 18800 (313%)

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 information (counted in megabytes per second) that can be transported over the external memory interface in one second. The number is calculated by multiplying the bus width by the speed of its memory. If the card has DDR memory, it should be multiplied by 2 again. If it uses 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 texture map elements (texels) that can be applied per second. This is worked out by multiplying the total amount of texture units of the card by the core clock speed of the chip. The better the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly write to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.