Radeon HD 4670 512MB vs Radeon HD 6770 1GB

Intro

Compare those specs to the Radeon HD 6770 1GB, which comes with GPU clock speed of 900 MHz, and 1024 MB of GDDR5 RAM set to run at 1050 MHz through a 128-bit bus. It also is comprised of 800 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 4670 512MB		70 Watts
Radeon HD 6770 1GB		108 Watts
	Difference: 38 Watts (54%)

Memory Bandwidth

Performance-wise, the Radeon HD 6770 1GB should theoretically be a lot superior to the Radeon HD 4670 512MB overall. (explain)

Radeon HD 6770 1GB		67200 MB/sec
Radeon HD 4670 512MB		32000 MB/sec
	Difference: 35200 (110%)

Texel Rate

The Radeon HD 6770 1GB is quite a bit (approximately 50%) better at anisotropic filtering than the Radeon HD 4670 512MB. (explain)

Radeon HD 6770 1GB		36000 Mtexels/sec
Radeon HD 4670 512MB		24000 Mtexels/sec
	Difference: 12000 (50%)

Pixel Rate

The Radeon HD 6770 1GB will be much (more or less 140%) more effective at FSAA than the Radeon HD 4670 512MB, and will be able to handle higher screen resolutions better. (explain)

Radeon HD 6770 1GB		14400 Mpixels/sec
Radeon HD 4670 512MB		6000 Mpixels/sec
	Difference: 8400 (140%)

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 (in units of megabytes per second) that can be transported past the external memory interface within a second. It's worked out by multiplying the card's interface width by its memory speed. If the card has DDR type RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed per second. This is calculated by multiplying the total texture units by the core clock speed of the chip. The higher the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one 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. Pixel rate is worked out by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.