Radeon HD 4770 vs Radeon HD 4830 1GB

Intro

Compare those specifications to the Radeon HD 4830 1GB, which makes use of a 55 nm design. AMD has clocked the core speed at 575 MHz. The GDDR4 RAM works at a frequency of 900 MHz on this specific model. It features 640(128x5) SPUs along with 32 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 4770		80 Watts
Radeon HD 4830 1GB		95 Watts
	Difference: 15 Watts (19%)

Memory Bandwidth

The Radeon HD 4830 1GB should theoretically be a small bit faster than the Radeon HD 4770 overall. (explain)

Radeon HD 4830 1GB		57600 MB/sec
Radeon HD 4770		51200 MB/sec
	Difference: 6400 (13%)

Texel Rate

The Radeon HD 4770 will be quite a bit (about 30%) better at texture filtering than the Radeon HD 4830 1GB. (explain)

Radeon HD 4770		24000 Mtexels/sec
Radeon HD 4830 1GB		18400 Mtexels/sec
	Difference: 5600 (30%)

Pixel Rate

If running with a high resolution is important to you, then the Radeon HD 4770 is a better choice, and very much so. (explain)

Radeon HD 4770		12000 Mpixels/sec
Radeon HD 4830 1GB		9200 Mpixels/sec
	Difference: 2800 (30%)

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 largest amount of data (counted in MB per second) that can be transported across the external memory interface in one second. The number is calculated by multiplying the card's interface width by its memory clock speed. If it uses DDR type RAM, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed per second. This is worked out by multiplying the total amount of texture units of the card 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 processed per second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly record to the local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the amount of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.