GeForce GTX 870M vs Radeon HD 4790

Intro

Compare those specifications to the Radeon HD 4790, which makes use of a 55 nm design. AMD has clocked the core speed at 600 MHz. The GDDR5 RAM works at a frequency of 800 MHz on this card. It features 640(128x5) SPUs along with 32 Texture Address Units and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

In theory, the Radeon HD 4790 should be just a bit faster than 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 is quite a bit (about 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

The GeForce GTX 870M will be much (more or less 135%) more effective at FSAA than the Radeon HD 4790, and capable of handling higher resolutions more effectively. (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: Memory bandwidth is the max amount of data (counted in MB per second) that can be transported across the external memory interface in a second. It's calculated by multiplying the bus width by its memory clock speed. If it uses DDR type memory, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed in one second. This number is calculated by multiplying the total texture units 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 processed in a second.

Pixel Rate: Pixel rate is the most pixels the graphics card can possibly record to the local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of colour ROPs 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 output rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.