Radeon HD 4830 1GB vs Radeon HD 6770 1GB

Intro

Compare all of that to the Radeon HD 6770 1GB, which comes with GPU clock speed of 900 MHz, and 1024 MB of GDDR5 memory set to run at 1050 MHz through a 128-bit bus. It also is made up 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 1GB		95 Watts
Radeon HD 6770 1GB		108 Watts
	Difference: 13 Watts (14%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 6770 1GB should be a little bit faster than the Radeon HD 4830 1GB overall. (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 is much (approximately 57%) better at anti-aliasing than the Radeon HD 4830 1GB, and also should be able to handle higher resolutions without slowing down too much. (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: Memory bandwidth is the max amount of data (in units of MB per second) that can be moved across the external memory interface in a second. The number is worked out by multiplying the interface width by its memory speed. If it uses DDR 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, High Dynamic Range and high resolutions.

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

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