Radeon HD 4670 1GB vs Radeon HD 6790

Intro

Compare those specs to the Radeon HD 6790, which comes with GPU clock speed of 840 MHz, and 1024 MB of GDDR5 memory set to run at 1050 MHz through a 256-bit bus. It also 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 6790		150 Watts
	Difference: 80 Watts (114%)

Memory Bandwidth

In theory, the Radeon HD 6790 should perform much 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 is much (more or less 40%) faster with regards to AF 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

If using a high screen resolution is important to you, then the Radeon HD 6790 is superior to the Radeon HD 4670 1GB, and very much so. (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: Memory bandwidth is the maximum amount of data (measured in megabytes per second) that can be transferred across the external memory interface within a second. The number is worked out by multiplying the card's bus width by its memory clock speed. If the card has DDR memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum number 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 better this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.

Pixel Rate: Pixel rate is the most pixels that the graphics card could possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Render Output Units by the the core clock speed. 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 fill rate also depends 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 maximum fill rate.