Radeon HD 4670 1GB vs Radeon HD 6770

Intro

Compare all that to the Radeon HD 6770, which features a core clock frequency of 900 MHz and a GDDR5 memory speed of 1050 MHz. It also features a 128-bit memory bus, and makes use of a 40 nm design. It 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 1GB		70 Watts
Radeon HD 6770		108 Watts
	Difference: 38 Watts (54%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 6770 is 91% faster than the Radeon HD 4670 1GB in general, due to its greater bandwidth. (explain)

Radeon HD 6770		67200 MB/sec
Radeon HD 4670 1GB		35200 MB/sec
	Difference: 32000 (91%)

Texel Rate

The Radeon HD 6770 will be a lot (approximately 50%) faster with regards to texture filtering than the Radeon HD 4670 1GB. (explain)

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

Pixel Rate

If running with a high resolution is important to you, then the Radeon HD 6770 is a better choice, and very much so. (explain)

Radeon HD 6770		14400 Mpixels/sec
Radeon HD 4670 1GB		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 max amount of data (counted in megabytes per second) that can be transported over the external memory interface in one second. The number is worked out by multiplying the bus width by its memory speed. In the case of DDR type memory, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied per second. This figure is calculated by multiplying the total amount of texture units by the core speed of the chip. The higher this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

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