Radeon HD 4670 512MB vs Radeon HD 6770

Intro

Compare that to the Radeon HD 6770, which comes with a clock frequency of 900 MHz and a GDDR5 memory speed of 1050 MHz. It also makes use of a 128-bit bus, and makes use of a 40 nm design. It features 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 4670 512MB		70 Watts
Radeon HD 6770		108 Watts
	Difference: 38 Watts (54%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 6770 will be 110% quicker than the Radeon HD 4670 512MB overall, due to its higher bandwidth. (explain)

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

Texel Rate

The Radeon HD 6770 will be quite a bit (about 50%) better at texture filtering than the Radeon HD 4670 512MB. (explain)

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

Pixel Rate

The Radeon HD 6770 will be much (approximately 140%) more effective at full screen anti-aliasing than the Radeon HD 4670 512MB, and will be able to handle higher resolutions without slowing down too much. (explain)

Radeon HD 6770		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: Bandwidth is the maximum amount of data (counted in MB per second) that can be transported across the external memory interface in one second. It's calculated by multiplying the bus width by its memory speed. If the card has DDR type RAM, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the better 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 number of texture map elements (texels) that are processed in one second. This figure is calculated by multiplying the total texture units by the core speed of the chip. The higher the texel rate, the better the card will be at handling 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 that the graphics chip can possibly write to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the amount of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also called 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, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the max fill rate.