Radeon HD 4830 1GB vs Radeon HD 6870

Intro

Compare those specs to the Radeon HD 6870, which makes use of a 40 nm design. AMD has set the core frequency at 900 MHz. The GDDR5 memory is set to run at a frequency of 1050 MHz on this specific card. 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 1GB		95 Watts
Radeon HD 6870		151 Watts
	Difference: 56 Watts (59%)

Memory Bandwidth

Theoretically, the Radeon HD 6870 should perform much faster than the Radeon HD 4830 1GB overall. (explain)

Radeon HD 6870		134400 MB/sec
Radeon HD 4830 1GB		57600 MB/sec
	Difference: 76800 (133%)

Texel Rate

The Radeon HD 6870 should be a lot (approximately 174%) more effective at anisotropic filtering than the Radeon HD 4830 1GB. (explain)

Radeon HD 6870		50400 Mtexels/sec
Radeon HD 4830 1GB		18400 Mtexels/sec
	Difference: 32000 (174%)

Pixel Rate

The Radeon HD 6870 will be a lot (more or less 213%) more effective at AA than the Radeon HD 4830 1GB, and able to handle higher screen resolutions better. (explain)

Radeon HD 6870		28800 Mpixels/sec
Radeon HD 4830 1GB		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: Memory bandwidth is the maximum amount of data (measured in megabytes per second) that can be transported over the external memory interface in a second. It is calculated by multiplying the interface width by the speed of its memory. In the case of DDR RAM, it should be multiplied by 2 once 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 amount of texture map elements (texels) that are applied per 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 card will be at handling 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 record to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the amount 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 also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.