Radeon HD 6770 1GB vs Radeon HD 7970

Intro

Compare those specifications to the Radeon HD 7970, which has GPU core speed of 925 MHz, and 3072 MB of GDDR5 memory running at 1375 MHz through a 384-bit bus. It also is comprised of 2048 SPUs, 128 Texture Address Units, and 32 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6770 1GB		108 Watts
Radeon HD 7970		250 Watts
	Difference: 142 Watts (131%)

Memory Bandwidth

As far as performance goes, the Radeon HD 7970 should in theory be quite a bit better than the Radeon HD 6770 1GB overall. (explain)

Radeon HD 7970		264000 MB/sec
Radeon HD 6770 1GB		67200 MB/sec
	Difference: 196800 (293%)

Texel Rate

The Radeon HD 7970 is much (about 229%) more effective at AF than the Radeon HD 6770 1GB. (explain)

Radeon HD 7970		118400 Mtexels/sec
Radeon HD 6770 1GB		36000 Mtexels/sec
	Difference: 82400 (229%)

Pixel Rate

The Radeon HD 7970 is much (about 106%) better at FSAA than the Radeon HD 6770 1GB, and capable of handling higher resolutions without losing too much performance. (explain)

Radeon HD 7970		29600 Mpixels/sec
Radeon HD 6770 1GB		14400 Mpixels/sec
	Difference: 15200 (106%)

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 max amount of information (in units of megabytes per second) that can be transferred across the external memory interface in one second. It is worked out by multiplying the interface width by the speed of its memory. If it uses DDR type RAM, it should be multiplied by 2 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 high resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly write to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the number of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.