Radeon HD 4830 1GB vs Radeon HD 6770 1GB

Intro

Compare that to the Radeon HD 6770 1GB, which comes with clock speeds of 900 MHz on the GPU, and 1050 MHz on the 1024 MB of GDDR5 memory. 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 6770 1GB		108 Watts
	Difference: 13 Watts (14%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 6770 1GB should be just a bit faster than the Radeon HD 4830 1GB in general. (explain)

Radeon HD 6770 1GB		67200 MB/sec
Radeon HD 4830 1GB		57600 MB/sec
	Difference: 9600 (17%)

Texel Rate

The Radeon HD 6770 1GB should be a lot (approximately 96%) faster with regards to texture filtering than the Radeon HD 4830 1GB. (explain)

Radeon HD 6770 1GB		36000 Mtexels/sec
Radeon HD 4830 1GB		18400 Mtexels/sec
	Difference: 17600 (96%)

Pixel Rate

The Radeon HD 6770 1GB should be a lot (more or less 57%) more effective at full screen anti-aliasing than the Radeon HD 4830 1GB, and will be capable of handling higher resolutions more effectively. (explain)

Radeon HD 6770 1GB		14400 Mpixels/sec
Radeon HD 4830 1GB		9200 Mpixels/sec
	Difference: 5200 (57%)

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 data (measured in megabytes per second) that can be transferred across the external memory interface within a second. The number is calculated by multiplying the card's interface width by the speed of its memory. In the case of DDR type RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly write to its local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the number of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.