Radeon HD 4830 512MB vs Radeon HD 6790

Intro

Compare those specifications to the Radeon HD 6790, which features core speeds of 840 MHz on the GPU, and 1050 MHz on the 1024 MB of GDDR5 RAM. It features 800 SPUs along with 40 Texture Address Units and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4830 512MB		95 Watts
Radeon HD 6790		150 Watts
	Difference: 55 Watts (58%)

Memory Bandwidth

In theory, the Radeon HD 6790 is 133% quicker than the Radeon HD 4830 512MB overall, due to its higher data rate. (explain)

Radeon HD 6790		134400 MB/sec
Radeon HD 4830 512MB		57600 MB/sec
	Difference: 76800 (133%)

Texel Rate

The Radeon HD 6790 will be much (about 83%) better at AF than the Radeon HD 4830 512MB. (explain)

Radeon HD 6790		33600 Mtexels/sec
Radeon HD 4830 512MB		18400 Mtexels/sec
	Difference: 15200 (83%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon HD 6790 is the winner, and very much so. (explain)

Radeon HD 6790		13440 Mpixels/sec
Radeon HD 4830 512MB		9200 Mpixels/sec
	Difference: 4240 (46%)

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 information (in units of MB per second) that can be transported over the external memory interface within a second. It's worked out by multiplying the card's interface width by the speed of its memory. In the case of DDR memory, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the 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 number of texture map elements (texels) that are processed in one second. This number is worked out by multiplying the total amount of texture units by the core speed of the chip. The better this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the most pixels the graphics card can possibly write to the 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 clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate also depends on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.