Radeon HD 4830 512MB vs Radeon HD 7770

Intro

Compare those specifications to the Radeon HD 7770, which comes with core clock speeds of 1000 MHz on the GPU, and 1125 MHz on the 1024 MB of GDDR5 memory. It features 640 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 7770		80 Watts
Radeon HD 4830 512MB		95 Watts
	Difference: 15 Watts (19%)

Memory Bandwidth

The Radeon HD 7770 should theoretically be a lot faster than the Radeon HD 4830 512MB overall. (explain)

Radeon HD 7770		72000 MB/sec
Radeon HD 4830 512MB		57600 MB/sec
	Difference: 14400 (25%)

Texel Rate

The Radeon HD 7770 is quite a bit (more or less 117%) faster with regards to AF than the Radeon HD 4830 512MB. (explain)

Radeon HD 7770		40000 Mtexels/sec
Radeon HD 4830 512MB		18400 Mtexels/sec
	Difference: 21600 (117%)

Pixel Rate

The Radeon HD 7770 is a lot (about 74%) better at FSAA than the Radeon HD 4830 512MB, and also able to handle higher resolutions more effectively. (explain)

Radeon HD 7770		16000 Mpixels/sec
Radeon HD 4830 512MB		9200 Mpixels/sec
	Difference: 6800 (74%)

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 information (measured in MB per second) that can be transported past the external memory interface in one second. It's worked out by multiplying the card's bus width by its memory clock speed. If the card has DDR type RAM, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed per second. This figure is calculated by multiplying the total texture units of the card by the core clock speed of the chip. The higher this number, the better the graphics card will be at handling 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 can possibly record to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.