Radeon HD 4670 1GB vs Radeon HD 6790

Intro

Compare all of that to the Radeon HD 6790, which makes use of a 40 nm design. AMD has clocked the core frequency at 840 MHz. The GDDR5 RAM is set to run at a speed of 1050 MHz on this specific card. It features 800 SPUs as well as 40 TAUs and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4670 1GB		70 Watts
Radeon HD 6790		150 Watts
	Difference: 80 Watts (114%)

Memory Bandwidth

In theory, the Radeon HD 6790 should perform a lot faster than the Radeon HD 4670 1GB in general. (explain)

Radeon HD 6790		134400 MB/sec
Radeon HD 4670 1GB		35200 MB/sec
	Difference: 99200 (282%)

Texel Rate

The Radeon HD 6790 should be a lot (approximately 40%) more effective at anisotropic filtering than the Radeon HD 4670 1GB. (explain)

Radeon HD 6790		33600 Mtexels/sec
Radeon HD 4670 1GB		24000 Mtexels/sec
	Difference: 9600 (40%)

Pixel Rate

The Radeon HD 6790 will be much (about 124%) faster with regards to anti-aliasing than the Radeon HD 4670 1GB, and also will be able to handle higher resolutions without losing too much performance. (explain)

Radeon HD 6790		13440 Mpixels/sec
Radeon HD 4670 1GB		6000 Mpixels/sec
	Difference: 7440 (124%)

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 data (counted in MB per second) that can be moved across the external memory interface in a second. It is worked out by multiplying the bus width by its memory speed. In the case of DDR type RAM, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the card's 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 per second. This figure is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The better the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly record to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the number of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.