GeForce GTX 870M vs Radeon HD 4790

Intro

Compare all of that to the Radeon HD 4790, which features a core clock speed of 600 MHz and a GDDR5 memory frequency of 800 MHz. It also uses a 256-bit bus, and uses a 55 nm design. It is made up of 640(128x5) 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 a bit superior to the GeForce GTX 870M in general. (explain)

Radeon HD 4790		102400 MB/sec
GeForce GTX 870M		96000 MB/sec
	Difference: 6400 (7%)

Texel Rate

The GeForce GTX 870M should be much (approximately 449%) more effective at texture filtering than the Radeon HD 4790. (explain)

GeForce GTX 870M		105392 Mtexels/sec
Radeon HD 4790		19200 Mtexels/sec
	Difference: 86192 (449%)

Pixel Rate

If running with a high resolution is important to you, then the GeForce GTX 870M is superior to the Radeon HD 4790, by far. (explain)

GeForce GTX 870M		22584 Mpixels/sec
Radeon HD 4790		9600 Mpixels/sec
	Difference: 12984 (135%)

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 transferred across the external memory interface within a second. The number is calculated by multiplying the card's interface width by the speed of its memory. If it uses DDR memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, the faster 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 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 card will be at 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 could possibly write to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.