Radeon HD 4670 1GB vs Radeon HD 6850

Intro

Compare that to the Radeon HD 6850, which has a 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 features 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 1GB		70 Watts
Radeon HD 6850		127 Watts
	Difference: 57 Watts (81%)

Memory Bandwidth

Performance-wise, the Radeon HD 6850 should in theory be a lot better than the Radeon HD 4670 1GB in general. (explain)

Radeon HD 6850		128000 MB/sec
Radeon HD 4670 1GB		35200 MB/sec
	Difference: 92800 (264%)

Texel Rate

The Radeon HD 6850 should be much (more or less 55%) more effective at texture filtering than the Radeon HD 4670 1GB. (explain)

Radeon HD 6850		37200 Mtexels/sec
Radeon HD 4670 1GB		24000 Mtexels/sec
	Difference: 13200 (55%)

Pixel Rate

The Radeon HD 6850 will be much (about 313%) better at anti-aliasing than the Radeon HD 4670 1GB, and also should be capable of handling higher screen resolutions while still performing well. (explain)

Radeon HD 6850		24800 Mpixels/sec
Radeon HD 4670 1GB		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 maximum amount of information (counted in megabytes per second) that can be transported across the external memory interface in one second. It's worked out by multiplying the bus width by its memory clock speed. If it uses DDR type RAM, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the bandwidth is, the faster 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 amount of texture map elements (texels) that are applied in one second. This figure is calculated by multiplying the total amount of texture units of the card by the core clock speed of the chip. The higher this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card could possibly write to the local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the amount of ROPs by the clock 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, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.