Radeon HD 4830 512MB vs Radeon HD 7770

Intro

Compare those specifications to the Radeon HD 7770, which has GPU core speed of 1000 MHz, and 1024 MB of GDDR5 RAM running at 1125 MHz through a 128-bit bus. It also is comprised of 640 SPUs, 40 Texture Address Units, and 16 ROPs.

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 in theory perform quite a bit 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

If using lots of anti-aliasing is important to you, then the Radeon HD 7770 is the winner, by a large margin. (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 maximum amount of data (measured in MB per second) that can be transported over the external memory interface in one second. The number is calculated by multiplying the card's interface width by its memory clock speed. If it uses DDR type memory, it should 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 higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly write to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel 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 get to the max fill rate.