Radeon HD 4730 vs Radeon HD 6870

Intro

Compare that to the Radeon HD 6870, which uses a 40 nm design. AMD has clocked the core speed at 900 MHz. The GDDR5 memory runs at a frequency of 1050 MHz on this specific model. It features 1120 SPUs along with 56 Texture Address Units and 32 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4730		140 Watts
Radeon HD 6870		151 Watts
	Difference: 11 Watts (8%)

Memory Bandwidth

In theory, the Radeon HD 6870 should perform much faster than the Radeon HD 4730 overall. (explain)

Radeon HD 6870		134400 MB/sec
Radeon HD 4730		57600 MB/sec
	Difference: 76800 (133%)

Texel Rate

The Radeon HD 6870 should be a lot (more or less 125%) better at anisotropic filtering than the Radeon HD 4730. (explain)

Radeon HD 6870		50400 Mtexels/sec
Radeon HD 4730		22400 Mtexels/sec
	Difference: 28000 (125%)

Pixel Rate

The Radeon HD 6870 is a lot (about 414%) better at AA than the Radeon HD 4730, and should be capable of handling higher resolutions more effectively. (explain)

Radeon HD 6870		28800 Mpixels/sec
Radeon HD 4730		5600 Mpixels/sec
	Difference: 23200 (414%)

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 (measured in megabytes per second) that can be transported over the external memory interface within a second. The number is calculated by multiplying the card's interface width by the speed of its memory. If the card has DDR RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed in one second. This is worked out by multiplying the total 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 in a second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly record 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 card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.