Radeon HD 6770 1GB vs Radeon HD 7790

Intro

Compare those specifications to the Radeon HD 7790, which makes use of a 28 nm design. AMD has set the core speed at 1000 MHz. The GDDR5 RAM runs at a frequency of 1500 MHz on this card. It features 896 SPUs along with 56 Texture Address Units and 16 ROPs.

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

Performance-wise, the Radeon HD 7790 should theoretically be a lot superior to 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 much (more or less 56%) more effective 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

The Radeon HD 7790 will be a bit (about 11%) more effective at AA than the Radeon HD 6770 1GB, and will be capable of handling higher resolutions better. (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: Bandwidth is the largest amount of information (in units of megabytes per second) that can be moved across the external memory interface in one second. It's calculated by multiplying the card's interface width by its memory speed. If the card has DDR memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the 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 number of texture map elements (texels) that can be applied in one second. This figure is calculated by multiplying the total texture units of the card by the core speed of the chip. The higher the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip could possibly record to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.