Radeon HD 4830 1GB vs Radeon HD 6770

Intro

Compare all of that to the Radeon HD 6770, which features a core clock speed of 900 MHz and a GDDR5 memory frequency of 1050 MHz. It also makes use of a 128-bit memory bus, and makes use of a 40 nm design. It is comprised of 800 SPUs, 40 TAUs, and 16 Raster Operation 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		108 Watts
	Difference: 13 Watts (14%)

Memory Bandwidth

In theory, the Radeon HD 6770 is 17% faster than the Radeon HD 4830 1GB in general, because of its higher data rate. (explain)

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

Texel Rate

The Radeon HD 6770 should be a lot (about 96%) more effective at anisotropic filtering than the Radeon HD 4830 1GB. (explain)

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

Pixel Rate

The Radeon HD 6770 should be much (approximately 57%) better at anti-aliasing than the Radeon HD 4830 1GB, and will be able to handle higher resolutions more effectively. (explain)

Radeon HD 6770		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 maximum amount of information (measured in megabytes per second) that can be moved past the external memory interface within a second. It's calculated by multiplying the card's bus width by the speed of its memory. If the card has DDR type RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, 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 better this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly write to the local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of colour ROPs by the clock speed of the card. 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 quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.