Radeon HD 4830 1GB vs Radeon HD 6870

Intro

Compare all that to the Radeon HD 6870, which has a clock speed of 900 MHz and a GDDR5 memory speed of 1050 MHz. It also features a 256-bit memory bus, and uses a 40 nm design. It features 1120 SPUs, 56 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 4830 1GB		95 Watts
Radeon HD 6870		151 Watts
	Difference: 56 Watts (59%)

Memory Bandwidth

In theory, the Radeon HD 6870 should be 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 will be much (approximately 174%) faster with regards to texture 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 should be a lot (more or less 213%) faster with regards to anti-aliasing than the Radeon HD 4830 1GB, and capable of handling higher 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: Bandwidth is the max amount of data (measured in megabytes per second) that can be transported past the external memory interface in a second. The number is calculated by multiplying the card's bus width by its memory speed. If it uses DDR memory, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the better 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 processed in one second. This is worked out by multiplying the total texture units by the core speed of the chip. The higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the most 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 Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.