Radeon HD 4790 vs Radeon HD 7950 3GB

Intro

Compare that to the Radeon HD 7950 3GB, which comes with a core clock frequency of 800 MHz and a GDDR5 memory speed of 1250 MHz. It also uses a 384-bit bus, and makes use of a 28 nm design. It is made up of 1792 SPUs, 112 TAUs, and 32 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Memory Bandwidth

In theory, the Radeon HD 7950 3GB should perform quite a bit faster than the Radeon HD 4790 overall. (explain)

Radeon HD 7950 3GB		240000 MB/sec
Radeon HD 4790		102400 MB/sec
	Difference: 137600 (134%)

Texel Rate

The Radeon HD 7950 3GB is a lot (approximately 367%) faster with regards to texture filtering than the Radeon HD 4790. (explain)

Radeon HD 7950 3GB		89600 Mtexels/sec
Radeon HD 4790		19200 Mtexels/sec
	Difference: 70400 (367%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon HD 7950 3GB is the winner, by a large margin. (explain)

Radeon HD 7950 3GB		25600 Mpixels/sec
Radeon HD 4790		9600 Mpixels/sec
	Difference: 16000 (167%)

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 (counted in megabytes per second) that can be transferred across the external memory interface within a second. The number is calculated by multiplying the card's bus width by its memory clock speed. If the card has DDR type RAM, it should be multiplied by 2 once 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, HDR and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This number is calculated by multiplying the total texture units by the core speed of the chip. The higher the texel rate, the better the video card will be at handling 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 card could possibly write to its local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.