Radeon HD 4790 vs Radeon HD 7750

Intro

Compare those specs to the Radeon HD 7750, which has GPU clock speed of 800 MHz, and 1024 MB of GDDR5 memory set to run at 1125 MHz through a 128-bit bus. It also is made up of 512 SPUs, 32 TAUs, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Memory Bandwidth

Performance-wise, the Radeon HD 4790 should in theory be quite a bit better than the Radeon HD 7750 in general. (explain)

Radeon HD 4790		102400 MB/sec
Radeon HD 7750		72000 MB/sec
	Difference: 30400 (42%)

Texel Rate

The Radeon HD 7750 will be a lot (approximately 33%) more effective at anisotropic filtering than the Radeon HD 4790. (explain)

Radeon HD 7750		25600 Mtexels/sec
Radeon HD 4790		19200 Mtexels/sec
	Difference: 6400 (33%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon HD 7750 is the winner, and very much so. (explain)

Radeon HD 7750		12800 Mpixels/sec
Radeon HD 4790		9600 Mpixels/sec
	Difference: 3200 (33%)

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 moved across the external memory interface in a second. It's worked out by multiplying the card's bus width by the speed of its memory. If it uses DDR type 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 AA, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied per second. This is calculated by multiplying the total texture units of the card by the core speed of the chip. The better this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can 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 Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.