GeForce GTX 870M vs Radeon HD 4870 2GB

Intro

Compare all of that to the Radeon HD 4870 2GB, which makes use of a 55 nm design. AMD has set the core frequency at 750 MHz. The GDDR5 memory is set to run at a speed of 900 MHz on this card. It features 800(160x5) SPUs along with 40 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 870M		110 Watts
Radeon HD 4870 2GB		150 Watts
	Difference: 40 Watts (36%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 4870 2GB should perform just a bit faster than the GeForce GTX 870M in general. (explain)

Radeon HD 4870 2GB		115200 MB/sec
GeForce GTX 870M		96000 MB/sec
	Difference: 19200 (20%)

Texel Rate

The GeForce GTX 870M will be a lot (about 251%) more effective at texture filtering than the Radeon HD 4870 2GB. (explain)

GeForce GTX 870M		105392 Mtexels/sec
Radeon HD 4870 2GB		30000 Mtexels/sec
	Difference: 75392 (251%)

Pixel Rate

If using a high resolution is important to you, then the GeForce GTX 870M is the winner, by far. (explain)

GeForce GTX 870M		22584 Mpixels/sec
Radeon HD 4870 2GB		12000 Mpixels/sec
	Difference: 10584 (88%)

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 (in units of MB per second) that can be moved over the external memory interface in a second. It is calculated by multiplying the interface width by its memory clock speed. If it uses DDR RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied per second. This figure is worked out by multiplying the total texture units by the core clock speed of the chip. The higher the texel rate, 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 could possibly write to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Render Output Units 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 rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.