GeForce GTX 850M vs Radeon HD 4870 2GB

Intro

Compare all of that to the Radeon HD 4870 2GB, which has a GPU core clock speed of 750 MHz, and 2048 MB of GDDR5 memory running at 900 MHz through a 256-bit bus. It also is made up of 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 850M		40 Watts
Radeon HD 4870 2GB		150 Watts
	Difference: 110 Watts (275%)

Memory Bandwidth

As far as performance goes, the Radeon HD 4870 2GB should theoretically be much better than the GeForce GTX 850M overall. (explain)

Radeon HD 4870 2GB		115200 MB/sec
GeForce GTX 850M		32000 MB/sec
	Difference: 83200 (260%)

Texel Rate

The GeForce GTX 850M will be a small bit (more or less 17%) better at texture filtering than the Radeon HD 4870 2GB. (explain)

GeForce GTX 850M		35040 Mtexels/sec
Radeon HD 4870 2GB		30000 Mtexels/sec
	Difference: 5040 (17%)

Pixel Rate

If running with lots of anti-aliasing is important to you, then the GeForce GTX 850M is the winner, but only just. (explain)

GeForce GTX 850M		14016 Mpixels/sec
Radeon HD 4870 2GB		12000 Mpixels/sec
	Difference: 2016 (17%)

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 information (measured in megabytes per second) that can be moved over the external memory interface within a second. It's worked out by multiplying the card's interface width by the speed of its memory. If the card has DDR memory, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied in one second. This figure is calculated by multiplying the total number of texture units of the card by the core clock 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 per second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly record to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.