Radeon HD 4830 1GB vs Radeon HD 6790

Intro

Compare that to the Radeon HD 6790, which uses a 40 nm design. AMD has set the core frequency at 840 MHz. The GDDR5 RAM is set to run at a speed of 1050 MHz on this specific model. It features 800 SPUs along with 40 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4830 1GB		95 Watts
Radeon HD 6790		150 Watts
	Difference: 55 Watts (58%)

Memory Bandwidth

Performance-wise, the Radeon HD 6790 should in theory be much superior to the Radeon HD 4830 1GB overall. (explain)

Radeon HD 6790		134400 MB/sec
Radeon HD 4830 1GB		57600 MB/sec
	Difference: 76800 (133%)

Texel Rate

The Radeon HD 6790 is quite a bit (approximately 83%) more effective at texture filtering than the Radeon HD 4830 1GB. (explain)

Radeon HD 6790		33600 Mtexels/sec
Radeon HD 4830 1GB		18400 Mtexels/sec
	Difference: 15200 (83%)

Pixel Rate

The Radeon HD 6790 should be much (about 46%) better at full screen anti-aliasing than the Radeon HD 4830 1GB, and capable of handling higher resolutions without losing too much performance. (explain)

Radeon HD 6790		13440 Mpixels/sec
Radeon HD 4830 1GB		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 largest amount of information (counted in MB per second) that can be moved across the external memory interface in one second. The number is worked out by multiplying the card's bus width by the speed of its memory. If it uses DDR memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed per second. This figure is calculated by multiplying the total amount of texture units by the core speed of the chip. The better this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.

Pixel Rate: Pixel rate is the most pixels the video card could possibly write to its 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 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, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.