Radeon HD 4770 vs Radeon HD 4830 512MB

Intro

Compare those specifications to the Radeon HD 4830 512MB, which uses a 55 nm design. AMD has clocked the core frequency at 575 MHz. The GDDR3 memory runs at a frequency of 900 MHz on this particular card. It features 640(128x5) SPUs as well as 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 512MB		95 Watts
	Difference: 15 Watts (19%)

Memory Bandwidth

The Radeon HD 4830 512MB, in theory, should be a bit faster than the Radeon HD 4770 overall. (explain)

Radeon HD 4830 512MB		57600 MB/sec
Radeon HD 4770		51200 MB/sec
	Difference: 6400 (13%)

Texel Rate

The Radeon HD 4770 should be much (approximately 30%) more effective at AF than the Radeon HD 4830 512MB. (explain)

Radeon HD 4770		24000 Mtexels/sec
Radeon HD 4830 512MB		18400 Mtexels/sec
	Difference: 5600 (30%)

Pixel Rate

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

Radeon HD 4770		12000 Mpixels/sec
Radeon HD 4830 512MB		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 max amount of data (counted in megabytes per second) that can be transferred over the external memory interface in a second. It's calculated by multiplying the card's bus width by its memory speed. In the case of DDR RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied in one second. This is worked out by multiplying the total number of texture units by the core clock speed of the chip. The better this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.

Pixel Rate: Pixel rate is the most pixels the graphics card can possibly record to the local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.