Radeon HD 4830 512MB vs Radeon HD 6770

Intro

Compare all that to the Radeon HD 6770, which has GPU clock speed of 900 MHz, and 512 MB of GDDR5 memory running at 1050 MHz through a 128-bit bus. It also is comprised of 800 SPUs, 40 TAUs, 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 6770		108 Watts
	Difference: 13 Watts (14%)

Memory Bandwidth

In theory, the Radeon HD 6770 should be 17% quicker than the Radeon HD 4830 512MB overall, due to its higher bandwidth. (explain)

Radeon HD 6770		67200 MB/sec
Radeon HD 4830 512MB		57600 MB/sec
	Difference: 9600 (17%)

Texel Rate

The Radeon HD 6770 is quite a bit (more or less 96%) faster with regards to AF than the Radeon HD 4830 512MB. (explain)

Radeon HD 6770		36000 Mtexels/sec
Radeon HD 4830 512MB		18400 Mtexels/sec
	Difference: 17600 (96%)

Pixel Rate

The Radeon HD 6770 should be much (more or less 57%) better at AA than the Radeon HD 4830 512MB, and also able to handle higher screen resolutions without slowing down too much. (explain)

Radeon HD 6770		14400 Mpixels/sec
Radeon HD 4830 512MB		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: Memory bandwidth is the maximum amount of data (counted in MB per second) that can be transported over the external memory interface in a second. It is calculated by multiplying the bus width by the speed of its memory. If the card has DDR type memory, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels the video card could possibly write to its local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Render Output Units by the the card's 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 output rate is also dependant on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the max fill rate.