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 set the core speed at 600 MHz. The GDDR5 memory is set to run at a speed of 800 MHz on this particular card. It features 640(128x5) SPUs as well as 32 Texture Address Units and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

Theoretically speaking, the Radeon HD 4790 will be 7% faster than the GeForce GTX 870M in general, because of its greater data rate. (explain)

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

Texel Rate

The GeForce GTX 870M will be a lot (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 is a lot (more or less 135%) more effective at AA than the Radeon HD 4790, and also will be able to handle higher screen resolutions better. (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 maximum amount of information (counted in MB per second) that can be moved across the external memory interface within a second. It's worked out by multiplying the card's interface width by its memory clock speed. If the card has DDR memory, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the most pixels that the graphics card can possibly record to its local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.