Radeon HD 6770 1GB vs Radeon HD 7790

Intro

Compare all of that to the Radeon HD 7790, which features core speeds of 1000 MHz on the GPU, and 1500 MHz on the 1024 MB of GDDR5 memory. It features 896 SPUs as well as 56 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7790		85 Watts
Radeon HD 6770 1GB		108 Watts
	Difference: 23 Watts (27%)

Memory Bandwidth

As far as performance goes, the Radeon HD 7790 should in theory be much better than the Radeon HD 6770 1GB overall. (explain)

Radeon HD 7790		96000 MB/sec
Radeon HD 6770 1GB		67200 MB/sec
	Difference: 28800 (43%)

Texel Rate

The Radeon HD 7790 should be a lot (approximately 56%) better at anisotropic filtering than the Radeon HD 6770 1GB. (explain)

Radeon HD 7790		56000 Mtexels/sec
Radeon HD 6770 1GB		36000 Mtexels/sec
	Difference: 20000 (56%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon HD 7790 is the winner, though not by far. (explain)

Radeon HD 7790		16000 Mpixels/sec
Radeon HD 6770 1GB		14400 Mpixels/sec
	Difference: 1600 (11%)

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 largest amount of data (counted in megabytes per second) that can be transferred over the external memory interface in a second. The number is calculated by multiplying the bus width by its memory speed. In the case of DDR type RAM, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the card's memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied in one second. This number is calculated by multiplying the total amount of texture units of the card by the core clock 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 maximum number of pixels that the graphics card can possibly write to its local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.