Radeon HD 4830 512MB vs Radeon HD 6870

Intro

Compare that to the Radeon HD 6870, which makes use of a 40 nm design. AMD has clocked the core frequency at 900 MHz. The GDDR5 RAM is set to run at a frequency of 1050 MHz on this specific model. It features 1120 SPUs as well as 56 Texture Address Units and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4830 512MB		95 Watts
Radeon HD 6870		151 Watts
	Difference: 56 Watts (59%)

Memory Bandwidth

As far as performance goes, the Radeon HD 6870 should theoretically be quite a bit superior to the Radeon HD 4830 512MB in general. (explain)

Radeon HD 6870		134400 MB/sec
Radeon HD 4830 512MB		57600 MB/sec
	Difference: 76800 (133%)

Texel Rate

The Radeon HD 6870 should be much (approximately 174%) better at texture filtering than the Radeon HD 4830 512MB. (explain)

Radeon HD 6870		50400 Mtexels/sec
Radeon HD 4830 512MB		18400 Mtexels/sec
	Difference: 32000 (174%)

Pixel Rate

The Radeon HD 6870 will be much (more or less 213%) more effective at FSAA than the Radeon HD 4830 512MB, and will be capable of handling higher resolutions without slowing down too much. (explain)

Radeon HD 6870		28800 Mpixels/sec
Radeon HD 4830 512MB		9200 Mpixels/sec
	Difference: 19600 (213%)

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 maximum amount of data (counted in megabytes per second) that can be transported past the external memory interface within a second. The number is worked out by multiplying the card's bus width by its memory speed. In the case of DDR type RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed in one second. This 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 video card will be at 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 video card can possibly record to its local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.