Radeon HD 4830 512MB vs Radeon HD 7870

Intro

Compare those specs to the Radeon HD 7870, which makes use of a 28 nm design. AMD has clocked the core speed at 1000 MHz. The GDDR5 memory works at a speed of 1200 MHz on this particular card. It features 1280 SPUs along with 80 TAUs and 32 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4830 512MB		95 Watts
Radeon HD 7870		175 Watts
	Difference: 80 Watts (84%)

Memory Bandwidth

Theoretically, the Radeon HD 7870 should perform a lot faster than the Radeon HD 4830 512MB in general. (explain)

Radeon HD 7870		153600 MB/sec
Radeon HD 4830 512MB		57600 MB/sec
	Difference: 96000 (167%)

Texel Rate

The Radeon HD 7870 should be quite a bit (about 335%) faster with regards to AF than the Radeon HD 4830 512MB. (explain)

Radeon HD 7870		80000 Mtexels/sec
Radeon HD 4830 512MB		18400 Mtexels/sec
	Difference: 61600 (335%)

Pixel Rate

The Radeon HD 7870 is quite a bit (more or less 248%) better at FSAA than the Radeon HD 4830 512MB, and also should be able to handle higher screen resolutions without losing too much performance. (explain)

Radeon HD 7870		32000 Mpixels/sec
Radeon HD 4830 512MB		9200 Mpixels/sec
	Difference: 22800 (248%)

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 largest amount of data (counted in megabytes per second) that can be transported across the external memory interface in a second. The number is worked out by multiplying the interface width by its memory speed. If the card has DDR type memory, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the bandwidth is, the better 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 can be processed in one second. This number is calculated by multiplying the total texture units 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 processed in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly write to the local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.